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  • 1.
    Bogoni, Antonella
    et al.
    Scuola Super Sant Anna, I-56127 Pisa, Italy..
    Mecozzi, Antonio
    Univ Aquila, Dept Phys & Chem Sci, I-67100 Laquila, Italy..
    Okonkwo, Chigo M.
    Eindhoven Univ Technol, NL-5612 AZ Eindhoven, Netherlands..
    Plant, David V.
    McGill Univ, Dept Elect & Comp Engn, Montreal, PQ, Canada..
    Saitoh, Kunimasa
    Hokkaido Univ, Elect Engn, Sapporo, Hokkaido 0600814, Japan.;Hokkaido Univ, Grad Sch Engn, Sapporo, Hokkaido 0600814, Japan.;Hokkaido Univ, Grad Sch Informat Sci & Technol, Sapporo, Hokkaido 0600814, Japan..
    Wosinska, Lena
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik. KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Liu, Gordon Ning
    Huawei Technol Co Ltd, Shenzhen 518129, Peoples R China..
    Umbach, Andreas
    AUCCEPT Consulting GmbH, D-14055 Berlin, Germany..
    Charlet, Gabriel
    Huawei Paris Res Ctr, F-75002 Paris, France..
    Gaudino, Roberto
    Politecn Torino, Dipartimento Elettron & Telecomunicaz, I-10129 Turin, Italy..
    Foreword to the Special Issue on the 44th European Conference on Optical Communication (ECOC 2018)2019Ingår i: Journal of Lightwave Technology, ISSN 0733-8724, E-ISSN 1558-2213, Vol. 37, nr 5, s. 1450-1455Artikel i tidskrift (Övrigt vetenskapligt)
  • 2.
    Cavallaro, Sara
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Horak, Josef
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Proteinvetenskap, Protein Engineering.
    Haag, Petra
    Karolinska Inst, Karolinska Univ Hosp, Dept Oncol Pathol, Theme Canc,Patient Area,Pelvis, Akad Straket 1, S-17164 Stockholm, Sweden..
    Gupta, Dhanu
    Karolinska Inst, Clin Res Ctr, Dept Lab Med, S-17177 Stockholm, Sweden.;Evox Therapeut Ltd, Oxford OX4 4HG, England..
    Stiller, Christiane
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Proteinvetenskap, Protein Engineering.
    Sahu, Siddharth S.
    Uppsala Univ, Angstrom Lab, Dept Solid State Elect, Box 534, SE-75121 Uppsala, Sweden..
    Gorgens, Andre
    Karolinska Inst, Clin Res Ctr, Dept Lab Med, S-17177 Stockholm, Sweden.;Evox Therapeut Ltd, Oxford OX4 4HG, England.;Univ Duisburg Essen, Univ Hosp Essen, Inst Transfus Med, D-45122 Essen, Germany..
    Gatty, Hithesh K.
    Uppsala Univ, Angstrom Lab, Dept Solid State Elect, Box 534, SE-75121 Uppsala, Sweden..
    Viktorsson, Kristina
    Karolinska Inst, Dept Oncol Pathol, Karolinska Univ Hosp, Theme Canc,Patient Area,Head & Neck Lung & Skin, Akad Straket 1, S-17164 Solna, Sweden..
    El Andaloussi, Samir
    Karolinska Inst, Clin Res Ctr, Dept Lab Med, S-17177 Stockholm, Sweden.;Evox Therapeut Ltd, Oxford OX4 4HG, England..
    Lewensohn, Rolf
    Karolinska Inst, Dept Oncol Pathol, Karolinska Univ Hosp, Theme Canc,Patient Area,Head & Neck Lung & Skin, Akad Straket 1, S-17164 Solna, Sweden..
    Eriksson Karlström, Amelie
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Proteinvetenskap, Protein Engineering. KTH Royal Inst Technol, Sch Engn Sci Chem Biotechnol & Hlth, Dept Prot Sci, AlbalNova Univ Ctr, S-10691 Stockholm, Sweden..
    Linnros, Jan
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik. KTH Royal Inst Technol, Sch Engn Sci, Dept Appl Phys, S-16440 Kista, Sweden..
    Dev, Apurba
    Uppsala Univ, Angstrom Lab, Dept Solid State Elect, Box 534, SE-75121 Uppsala, Sweden..
    Label-Free Surface Protein Profiling of Extracellular Vesicles by an Electrokinetic Sensor2019Ingår i: ACS SENSORS, ISSN 2379-3694, Vol. 4, nr 5, s. 1399-1408Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Small extracellular vesicles (sEVs) generated from the endolysosomal system, often referred to as exosomes, have attracted interest as a suitable biomarker for cancer diagnostics, as they carry valuable biological information and reflect their cells of origin. Herein, we propose a simple and inexpensive electrical method for label-free detection and profiling of sEVs in the size range of exosomes. The detection method is based on the electrokinetic principle, where the change in the streaming current is monitored as the surface markers of the sEVs interact with the affinity reagents immobilized on the inner surface of a silica microcapillary. As a proof-of-concept, we detected sEVs derived from the non-small-cell lung cancer (NSCLC) cell line H1975 for a set of representative surface markers, such as epidermal growth factor receptor (EGFR), CD9, and CD63. The detection sensitivity was estimated to be similar to 175000 sEVs, which represents a sensor surface coverage of only 0.04%. We further validated the ability of the sensor to measure the expression level of a membrane protein by using sEVs displaying artificially altered expressions of EGFR and CD63, which were derived from NSCLC and human embryonic kidney (HEK) 293T cells, respectively. The analysis revealed that the changes in EGFR and CD63 expressions in sEVs can be detected with a sensitivity in the order of 10% and 3%, respectively, of their parental cell expressions. The method can be easily parallelized and combined with existing microfluidic-based EV isolation technologies, allowing for rapid detection and monitoring of sEVs for cancer diagnosis.

  • 3.
    Chen, Hui
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Baitenov, Adil
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Li, Yuanyuan
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Vasileva, Elena
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Popov, Sergei
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Sychugov, Ilya
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Yan, Min
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Berglund, Lars
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Thickness Dependence of Optical Transmittance of Transparent Wood: Chemical Modification Effects2019Ingår i: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 11, nr 38, s. 35451-35457Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Transparent wood (TW) is an emerging optical material combining high optical transmittance and haze for structural applications. Unlike nonscattering absorbing media, the thickness dependence of light transmittance for TW is complicated because optical losses are also related to increased photon path length from multiple scattering. In the present study, starting from photon diffusion equation, it is found that the angle-integrated total light transmittance of TW has an exponentially decaying dependence on sample thickness. The expression reveals an attenuation coefficient which depends not only on the absorption coefficient but also on the diffusion coefficient. The total transmittance and thickness were measured for a range of TW samples, from both acetylated and nonacetylated balsa wood templates, and were fitted according to the derived relationship. The fitting gives a lower attenuation coefficient for the acetylated TW compared to the nonacetylated one. The lower attenuation coefficient for the acetylated TW is attributed to its lower scattering coefficient or correspondingly lower haze. The attenuation constant resulted from our model hence can serve as a singular material parameter that facilitates cross-comparison of different sample types, at even different thicknesses, when total optical transmittance is concerned. The model was verified with two other TWs (ash and birch) and is in general applicable to other scattering media.

  • 4. Chen, X.
    et al.
    Lin, R.
    Cui, J.
    Gan, L.
    Pang, Xiaodan
    KTH, Skolan för elektroteknik och datavetenskap (EECS).
    Ozolins, O.
    Udalcovs, A.
    Jiang, T.
    Schatz, Richard
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Popov, Sergei
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Chen, Jiajia
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Tang, M.
    Fu, S.
    Liu, D.
    TDHQ Enabling Fine-Granularity Adaptive Loading for SSB-DMT Systems2018Ingår i: IEEE Photonics Technology Letters, ISSN 1041-1135, E-ISSN 1941-0174, Vol. 30, nr 19, s. 1687-1690, artikel-id 8443443Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this letter, we introduce time domain hybrid quadrature amplitude modulation (TDHQ) for the single sideband discrete multi-tone systems. The experimental results reveal that with a single precoding set and the proposed adaptive loading algorithm, the TDHQ scheme can achieve finer granularity and therefore smoother continuous growth of data rate than that with the conventional quadrature amplitude modulation. Besides, thanks to the frame construction and the tailored mapping rule, the scheme with TDHQ has an obviously better peak to an average power ratio. 

  • 5.
    Chung, Nguyen Xuan
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Limpens, Rens
    de Weerd, Chris
    Lesage, Arnon
    KTH.
    Fujii, Minoru
    Gregorkiewicz, Tom
    Toward Practical Carrier Multiplication: Donor/Acceptor Codoped Si Nanocrystals in SiO22018Ingår i: ACS Photonics, E-ISSN 2330-4022, Vol. 5, nr 7, s. 2843-2849Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Carrier multiplication (CM) is an interesting fundamental phenomenon with application potential in optoelectronics and photovoltaics, and it has been shown to be promoted by quantum confinement effects in nanostructures. However, mostly due to the short lifetimes of additional electronhole (e-h) pairs generated by CM, major improvements of quantum dot devices that exploit CM are limited. Here we investigate CM in SiO2 solid state dispersions of phosphorus and boron codoped Si nanocrystals (NCs): an exotic variant of Si NCs whose photoluminescence (PL) emission energy, the optical bandgap, is significantly red-shifted in comparison to undoped Si NCs. By combining the results obtained by ultrafast induced absorption (IA) with PL quantum yield (PL QY) measurements, we demonstrate CM with a long (around 100 mu s) lifetime of the additional e-h pairs created by the process, similar as previously reported for undoped Si NCs, but with a significantly lower CM threshold energy. This constitutes a significant step toward the practical implementation of Si-based NCs in optoelectronic devices: we demonstrate efficient CM at the energy bandgap optimal for photovoltaic conversion.

  • 6.
    Da Ros, F.
    et al.
    Tech Univ Denmark, DTU Foton, DK-2800 Lyngby, Denmark..
    Cristofori, V.
    Tech Univ Denmark, DTU Foton, DK-2800 Lyngby, Denmark..
    Ozolins, O.
    Acreo Swedish ICT, NETLAB, SE-16425 Kista, Sweden..
    Chaibi, M. E.
    Univ Rennes 1, CNRS, ENSSAT, FOTON Lab,UMR 6082, F-22305 Lannion, France..
    Pang, X.
    Acreo Swedish ICT, NETLAB, SE-16425 Kista, Sweden..
    Jacobsen, G.
    Acreo Swedish ICT, NETLAB, SE-16425 Kista, Sweden..
    Popov, Sergei
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Galili, M.
    Tech Univ Denmark, DTU Foton, DK-2800 Lyngby, Denmark..
    Oxenlowe, L. K.
    Tech Univ Denmark, DTU Foton, DK-2800 Lyngby, Denmark..
    Peucheret, C.
    Univ Rennes 1, CNRS, ENSSAT, FOTON Lab,UMR 6082, F-22305 Lannion, France..
    4-PAM Dispersion-Uncompensated Transmission with Micro-Ring Resonator Enhanced 1.55-mu m DML2017Ingår i: 2017 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO), IEEE , 2017Konferensbidrag (Refereegranskat)
    Abstract [en]

    Real-time transmission of 14-GBd 4-PAM signal is demonstrated by combining a commercial 1.55-mu m DML with a silicon MRR. BER below the HD-FEC threshold is measured after 26-km SSMF transmission without offline digital signal processing.

  • 7.
    Deniel, L.
    et al.
    Univ Paris Sud, Univ Paris Saclay, CNRS, Ctr Nanosci & Nanotechnol, F-91120 Palaiseau, France..
    Gay, M.
    Univ Rennes, CNRS, FOTON, UMR 6082, F-22305 Lannion, France..
    Perez Galacho, D.
    Univ Paris Sud, Univ Paris Saclay, CNRS, Ctr Nanosci & Nanotechnol, F-91120 Palaiseau, France.;Univ Politecn Valencia, ITEAM Res Inst, Camino Vera S-N, E-46022 Valencia, Spain..
    Baudot, C.
    ST Microelect, 850 Rue Jean Monnet, F-38920 Crolles, France..
    Bramerie, L.
    Univ Rennes, CNRS, FOTON, UMR 6082, F-22305 Lannion, France..
    Ozolins, Oskars
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Boeuf, F.
    ST Microelect, 850 Rue Jean Monnet, F-38920 Crolles, France..
    Vivien, L.
    Univ Paris Sud, Univ Paris Saclay, CNRS, Ctr Nanosci & Nanotechnol, F-91120 Palaiseau, France..
    Peucheret, C.
    Univ Rennes, CNRS, FOTON, UMR 6082, F-22305 Lannion, France..
    Marris-Morini, D.
    Univ Paris Sud, Univ Paris Saclay, CNRS, Ctr Nanosci & Nanotechnol, F-91120 Palaiseau, France..
    DAC-less PAM-4 generation in the O-band using a silicon Mach-Zehnder modulator2019Ingår i: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 27, nr 7, s. 9740-9748Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We demonstrate 20-Gb/s 4-level pulse amplitude modulation (PAM-4) signal generation using a silicon Mach-Zehnder modulator (MZM) in the O-band. The modulator is driven by two independent binary streams. and the PAM-4 signal is thus generated directly on the chip, avoiding the use of power-hungry digital-to-analog converters (DACs). With optimized amplitude levels of the binary signals applied to the two arms of the MZM, a pre-forward error correction (FEC) bit-error rate (BER) as low as 7.6 x 10(-7) is obtained. In comparison with a commercially available LiNbO3 modulator, the penalty is only 2 dB at the KP4 FEC threshold of 2.2 x 10(-4).

  • 8.
    Estaran, Jose Manuel
    et al.
    Nokia Bell Labs, F-91620 Nozay, France..
    Mardoyan, Haik
    Nokia Bell Labs, F-91620 Nozay, France..
    Jorge, Filipe
    Joint Lab Nokia Bell Labs Thales Res & Technol, Lab 3 5, F-91767 Palaiseau, France.;CEA Leti, F-91767 Palaiseau, France..
    Ozolins, Oskars
    RISE Acreo AB, Networking & Transmiss Lab, S-16425 Kista, Sweden..
    Udalcovs, Aleksejs
    RISE Acreo AB, Networking & Transmiss Lab, S-16425 Kista, Sweden..
    Konczykowska, Agnieszka
    Joint Lab Nokia Bell Labs Thales Res & Technol, Lab 3 5, F-91767 Palaiseau, France.;CEA Leti, F-91767 Palaiseau, France..
    Riet, Muriel
    Joint Lab Nokia Bell Labs Thales Res & Technol, Lab 3 5, F-91767 Palaiseau, France.;CEA Leti, F-91767 Palaiseau, France..
    Duval, Bernadette
    Joint Lab Nokia Bell Labs Thales Res & Technol, Lab 3 5, F-91767 Palaiseau, France.;CEA Leti, F-91767 Palaiseau, France..
    Nodjiadjim, Virginie
    Joint Lab Nokia Bell Labs Thales Res & Technol, Lab 3 5, F-91767 Palaiseau, France.;CEA Leti, F-91767 Palaiseau, France..
    Dupuy, Jean-Yves
    Joint Lab Nokia Bell Labs Thales Res & Technol, Lab 3 5, F-91767 Palaiseau, France.;CEA Leti, F-91767 Palaiseau, France..
    Pang, Xiaodan
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Westergren, Urban
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Chen, Jiajia
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Popov, Sergei
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Bigo, Sebastien
    Nokia Bell Labs, F-91620 Nozay, France..
    140/180/204-Gbaud OOK Transceiver for Inter- and Intra-Data Center Connectivity2019Ingår i: Journal of Lightwave Technology, ISSN 0733-8724, E-ISSN 1558-2213, Vol. 37, nr 1, s. 178-187Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We report on an ON OFF keying intensity-modulation and direct-detection C-band optical transceiver capable of addressing all datacenter interconnect environments at well beyond 100 Gbaud. For this, the transmitter makes the use of two key InP technologies: a 2:1 double heterojunction bipolar transistor selector multiplexer and a monolithically integrated distributed feedback laser traveling-wave electro-absorption modulator, both exceeding 100-GHz of 3-dB analog bandwidth. A preamplified 110-Gaz PIN photodiode prior to a 100-CHs analog-to-digital converter complete the ultrahigh bandwidth transceiver module; the device under study. In the experimental work, which discriminates between intra- and inter-data center scenarios (dispersion unmanaged 120, 560, and 960 m; and dispersion-managed 10 and 80 km of standard single-mode fiber), we evaluate the bit-error rate evolution against the received optical power at 140, 180, and 204 Gbaud ON OFF keying for different equalization configurations (adaptive linear filter with and without the help of short-memory sequence estimation) and forward error correction schemes (hard-decision codes with 7% and 20% overhead); drawing conclusions from the observed system-level limitations of the respective environments at this ultrahigh baudrate, as well as from the operation margins and sensitivity metrics. From the demonstration, we highlight three results: successful operation with >6-dB sensitivity margin below the 7% error-correction at 140 Gbaud over the entire 100 m-80 km range with only linear feed-forward equalization. Then, the transmission of a 180-Gbaud ON OFF keying carrier over 80 km considering 20% error-correction overhead. Finally, a 10-km communication at 204 (Maud ON OFF keying with up to 6 dB sensitivity margin, and regular 7% overhead error-correction.

  • 9.
    Gaiarin, Simone
    et al.
    DTU Fotonik, Technical University of Denmark, Kgs. Lyngby, 2800, Denmark.
    Pang, Xiaodan
    Acreo Swedish ICT AB, Isafjordsgatan 22, Kista, 164 40, Sweden.
    Ozolins, Oskars
    Acreo Swedish ICT AB, Isafjordsgatan 22, Kista, 164 40, Sweden.
    Jones, Rasmus T
    DTU Fotonik, Technical University of Denmark, Kgs. Lyngby, 2800, Denmark.
    Da Silva, Edson Porto
    DTU Fotonik, Technical University of Denmark, Kgs. Lyngby, 2800, Denmark.
    Schatz, Richard
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Westergren, Urban
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Popov, Sergei
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Jacobsen, Gunnar
    Acreo Swedish ICT AB, Isafjordsgatan 22, Kista, 164 40, Sweden.
    Zibar, Darko
    DTU Fotonik, Technical University of Denmark, Kgs. Lyngby, 2800, Denmark.
    High speed PAM-8 optical interconnects with digital equalization based on neural network2016Ingår i: Asia Communications and Photonics Conference, Optical Society of America, 2016Konferensbidrag (Refereegranskat)
    Abstract [en]

    We experimentally evaluate a high-speed optical interconnection link with neural network equalization. Enhanced equalization performances are shown comparing to standard linear FFE for an EML-based 32 GBd PAM-8 signal after 4-km SMF transmission.

  • 10. Greben, Michael
    et al.
    Khoroshyy, Petro
    Sychugov, Ilya
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Valenta, Jan
    Non-exponential decay kinetics: Correct assessment and description illustrated by slow luminescence of Si nanostructures2019Ingår i: Applied spectroscopy reviews (Softcover ed.), ISSN 0570-4928, E-ISSN 1520-569X, Vol. 54, s. 758-801Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The treatment of time-resolved (TR) photoluminescence (PL) decay kinetics is analysed in details and illustrated by experiments on semiconductor quantum dots, namely silicon nanocrystals (Si NCs). We consider the mono-, stretch- and multi-exponential as well as lognormal (LN) and some complex decay models for continuous and discrete distribution of rates (lifetimes). A particular attention is devoted to the thorough analysis of non-exponential decay kinetics. We explicitly show that a LN distribution of emitter sizes may results in LN distribution of decay rates. On the other hand, the distribution of rates cannot be, strictly speaking, Levy stable distribution (that results in the stretched-exponential decay). We introduce theoretical background and derive expressions to calculate the average decay lifetimes for some common decays with practical examples of their applications. Experimental aspects are discussed with special attention devoted to the major problems of the accurate TR PL data treatment, including background uncertainty, pulse duration, system response function etc. Finally, a thorough literature survey of TR PL in Si NCs is given. The methods and definitions outlined in this systematic review are applicable to various other material systems with slow decay like rare-earth and transition metal-doped materials, amorphous semiconductors, type-II heterostructures, singlet oxygen phosphorescence etc.

  • 11.
    Hong, Xuezhi
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT). South China Normal Univ, ZJU SCNU Joint Res Ctr Photon, Guangzhou, Guangdong, Peoples R China..
    Zhang, Lu
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Pang, Xiaodan
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab). RISE Acreo AB, Networking & Transmiss Lab, Kista, Sweden..
    Ozolins, Oskars
    RISE Acreo AB, Networking & Transmiss Lab, Kista, Sweden..
    Udalcovs, Aleksejs
    RISE Acreo AB, Networking & Transmiss Lab, Kista, Sweden..
    Guo, Changjian
    South China Normal Univ, ZJU SCNU Joint Res Ctr Photon, Guangzhou, Guangdong, Peoples R China..
    Nordwall, Fredrik
    Tektronix AB, Stockholm, Sweden..
    Engenhardt, Klaus M.
    Tektronix GmbH, Stuttgart, Germany..
    Kakkar, Aditya
    KTH, Skolan för elektroteknik och datavetenskap (EECS).
    Rodrigo Navarro, Jaime
    KTH, Skolan för elektroteknik och datavetenskap (EECS).
    Schatz, Richard
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Westergren, Urban
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Jacobsen, Gunnar
    RISE Acreo AB, Networking & Transmiss Lab, Kista, Sweden..
    Popov, Sergei
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Xiao, Shilin
    Shanghai Jiao Tong Univ, State Key Lab Adv Opt Commun Syst & Networks, Shanghai, Peoples R China..
    Chen, Jiajia
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    200-Gbps DMT Transmission over 1.6-km SSMF with A Single EML/DAC/PD for Optical Interconnects at C-Band2017Ingår i: 43RD EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION (ECOC 2017), IEEE , 2017Konferensbidrag (Refereegranskat)
    Abstract [en]

    We report on the first experimental demonstration of 200-Gbps (net rate 166.7-Gbps) 1.55-mu m DMT IMDD transmission over 1.6 km fiber using a single monolithically-integrated-EML, DAC and photodiode, achieving an effective electrical spectrum efficiency of 4.93 bit/s/Hz.

  • 12.
    Horak, Josef
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Proteinvetenskap, Protein Engineering.
    Jansson, Ronnie
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Proteinvetenskap, Protein Engineering.
    Dev, Apurba
    Uppsala Univ, Ångström Lab, Solid State Elect, Uppsala Box 534, SE-75121 Uppsala, Sweden..
    Nilebäck, Linnea
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Proteinvetenskap, Protein Engineering.
    Behnam, Kiarash
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Proteinvetenskap, Protein Engineering.
    Linnros, Jan
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Hedhammar, My
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Proteinvetenskap, Protein Engineering.
    Eriksson Karlström, Amelie
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Proteinvetenskap, Protein Engineering.
    Recombinant Spider Silk as Mediator for One-Step, Chemical-Free Surface Biofunctionalization2018Ingår i: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 28, nr 21, artikel-id 1800206Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A unique strategy for effective, versatile, and facile surface biofunctionalization employing a recombinant spider silk protein genetically functionalized with the antibody-binding Z domain (Z-4RepCT) is reported. It is demonstrated that Z-silk can be applied to a variety of materials and platform designs as a truly one-step and chemical-free surface modification that site specifically captures antibodies while simultaneously reducing nonspecific adsorption. As a model surface, SiO2 is used to optimize and characterize Z-silk performance compared to the Z domain immobilized by a standard silanization method. First, Z-silk adsorption is investigated and verified its biofunctionality in a long-term stability experiment. To assess the binding capacity and protein-protein interaction stability of Z-silk, the coating is used to capture human antibodies in various assay formats. An eightfold higher binding capacity and 40-fold lower detection limit are obtained in the immunofluorescence assay, and the complex stability of captured antibodies is shown to be improved by a factor of 20. Applicability of Z-silk to functionalize microfluidic devices is demonstrated by antibody detection in an electrokinetic microcapillary biosensor. To test Z-silk for biomarker applications, real-time detection and quantification of human immunoglobulin G are performed in a plasma sample and C1q capture from human serum using an anti-C1q antibody.

  • 13. Hu, H.
    et al.
    Jia, S.
    Lo, M. -C
    Zhang, Lu
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab). School of SE-IEE, Shanghai Jiao Tong University, Shanghai, 200240, China.
    Ozolins, O.
    Udalcovs, A.
    Kong, D.
    Pang, Xiaodan
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Yu, X.
    Xiao, S.
    Popov, Sergei
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Chen, Jiajia
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS.
    Carpintero, G.
    Morioka, T.
    Oxenlowe, L.
    TuB4.1-chip based thz emitter for ultra-high speed THz wireless communication (Invited)2019Ingår i: IEEE Photonics Society Summer Topical Meeting Series 2019, SUM 2019, Institute of Electrical and Electronics Engineers (IEEE), 2019, artikel-id 8794888Konferensbidrag (Refereegranskat)
    Abstract [en]

    By using a monolithically integrated dual-distributed feedback (DFB) laser chip attached to a photomixing uni-Travelling carrier photodiode (UTC-PD) with a THz antenna, single-channel THz photonic-wireless transmission system with a net rate of 131 Gbit/s over a wireless distance of 10.7 m has been achieved.

  • 14.
    Koivurova, Matias
    et al.
    Univ Eastern Finland, Inst Photon, POB 111, FI-80101 Joensuu, Finland..
    Vasileva, Elena
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Li, Yuanyuan
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Berglund, Lars
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Popov, Sergei
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Complete spatial coherence characterization of quasi-random laser emission from dye doped transparent wood2018Ingår i: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 26, nr 10, s. 13474-13482Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We report on the experimental determination of the complete two coordinate spatial coherence function of light emitted by a quasi-random laser, implemented on recently introduced dye-doped transparent wood. The spatial coherence was measured by means of a double grating interferometer, which has some advantages over the standard Young's interferometer. Analysis of the spatial coherence reveals that emission from such a material can be considered as a superposition of several spatial modes produced by individual emitters within semi-ordered scattering medium. The overall degree of coherence, (gamma)over-bar, for this quasi-random laser was found to be 0.16 +/- 0.01, having possible applications in speckle free laser imaging and illumination.

  • 15.
    Lavrinovica, Ingrida
    et al.
    Riga Tech Univ, Inst Telecommun, Azenes St 12, LV-1048 Riga, Latvia..
    Supe, Andis
    Riga Tech Univ, Inst Telecommun, Azenes St 12, LV-1048 Riga, Latvia..
    Udalcovs, Aleksejs
    RISE Acreo AB, Isafjordsgatan 22, S-16440 Kista, Sweden..
    Ozolins, Oskars
    RISE Acreo AB, Isafjordsgatan 22, S-16440 Kista, Sweden..
    Popov, Sergei
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Porins, Jurgis
    Riga Tech Univ, Inst Telecommun, Azenes St 12, LV-1048 Riga, Latvia..
    Exploration of Optical Amplifiers Based on Erbium (Er3+) and Ytterbium (Yb3+) Doped Fiber Segments and Its Emerging Applications2018Ingår i: 2018 Progress in Electromagnetics Research Symposium (PIERS-TOYAMA) / [ed] Chew, WC He, S, IEEE, 2018, s. 237-240, artikel-id 8598244Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper proposes the improvement of EDFA amplifier properties by adding additional segments of Yb3+ doped fiber. Experimental demonstration of a combined erbium ytterbium doped fiber amplifier (EYDFA) performance using 5m long erbium-doped fiber (EDF) and 5 m long ytterbium-doped fiber (YDF) is presented.

  • 16.
    Lin, Rui
    et al.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Lu, Yang
    Pang, Xiaodan
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Ozolins, Oskars
    RISE Acreo AB, Networking & Transmiss Lab, SE-16425 Kista, Sweden..
    Cheng, Yuxin
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Udalcovs, Aleksejs
    RISE Acreo AB, Networking & Transmiss Lab, SE-16425 Kista, Sweden..
    Popov, Sergei
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Jacobsen, Gunnar
    RISE Acreo AB, Networking & Transmiss Lab, SE-16425 Kista, Sweden..
    Tang, Ming
    Huazhong Univ Sci & Technol, Sch Opt & Elect Informat, Wuhan 430074, Hubei, Peoples R China..
    Liu, Deming
    Huazhong Univ Sci & Technol, Sch Opt & Elect Informat, Wuhan 430074, Hubei, Peoples R China..
    Chen, Jiajia
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    First Experimental Demonstration of Physical-Layer Network Coding in PAM4 System for Passive Optical Interconnects2017Ingår i: 43RD EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION (ECOC 2017), IEEE , 2017Konferensbidrag (Refereegranskat)
    Abstract [en]

    We propose to implement physical-layer network coding (PLNC) in coupler-based passive optical interconnects. The PLNC over PAM4 system is for the first time experimentally validated, where simultaneous mutual communications can be kept within the same wavelength channel, doubling spectrum efficiency.

  • 17.
    Lin, Rui
    et al.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Pang, Xiaodan
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Van Kerrebrouck, J.
    Belgium.
    Verplaetse, M.
    Belgium.
    Ozolins, O.
    Udalcovs, A.
    Zhang, Lu
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Gan, L.
    China.
    Tang, M.
    China.
    Fu, S.
    China.
    Schatz, Richard
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Westergren, Urban
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Popov, Sergei
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Liu, D.
    China.
    Tong, W.
    China.
    De Keulenaer, T.
    Belgium.
    Torfs, G.
    Belgium.
    Bauwelinck, J.
    Belgium.
    Yin, X.
    Belgium.
    Chen, Jiajia
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Real-time 100 Gbps/λ/core NRZ and EDB IM/DD transmission over 10 km multicore fiber2018Ingår i: Optics InfoBase Conference Papers, Optical Society of America, 2018Konferensbidrag (Refereegranskat)
    Abstract [en]

    A BiCMOS chip-based real-time IM/DD spatial division multiplexing system is experimentally demonstrated for short-reach communications. 100 Gbps/λ/core NRZ and EDB transmission is achieved below 7%-overhead HD-FEC limit after 10km 7-core fiber with optical dispersion compensation.

  • 18.
    Lin, Rui
    et al.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Udalcovs, A.
    Ozolins, O.
    Pang, Xiaodan
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Gan, L.
    Shen, L.
    Tang, M.
    Fu, S.
    Popov, Sergei
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Yang, C.
    Tong, W.
    Liu, D.
    Da Silva, T. F.
    Xavier, G. B.
    Chen, Jiajia
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Telecom Compatibility Validation of Quantum Key Distribution Co-Existing with 112 Gbps/λ/core Data Transmission in Non-Trench and Trench-Assistant Multicore Fibers2018Ingår i: European Conference on Optical Communication, ECOC, Institute of Electrical and Electronics Engineers Inc. , 2018Konferensbidrag (Refereegranskat)
    Abstract [en]

    We experimentally characterize photon leakage from 112Gb/s data channels in both non-trench and trench-assistant 7-core fibers, demonstrating telecom compatibility for QKD co-existing with high-speed data transmission when a proper core/wavelength allocation is carried out.

  • 19.
    Lin, Rui
    et al.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab). Huazhong Univ Sci & Technol, Wuhan, Hubei, Peoples R China..
    Van Kerrebrouck, Joris
    Univ Ghent, Imec, IDLab, Dept Informat Technol, Ghent, Belgium..
    Pang, Xiaodan
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab). RISE Acreo AB, Networking & Transmiss Lab, Kista, Sweden..
    Verplaetse, Michiel
    Univ Ghent, Imec, IDLab, Dept Informat Technol, Ghent, Belgium..
    Ozolins, Oskars
    RISE Acreo AB, Networking & Transmiss Lab, Kista, Sweden..
    Udalcovs, Aleksejs
    RISE Acreo AB, Networking & Transmiss Lab, Kista, Sweden..
    Zhang, Lu
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Gan, Lin
    Huazhong Univ Sci & Technol, Wuhan, Hubei, Peoples R China..
    Tang, Ming
    Huazhong Univ Sci & Technol, Wuhan, Hubei, Peoples R China..
    Fu, Songnian
    Huazhong Univ Sci & Technol, Wuhan, Hubei, Peoples R China..
    Schatz, Richard
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Westergren, Urban
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Popov, Sergei
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Liu, Deming
    Huazhong Univ Sci & Technol, Wuhan, Hubei, Peoples R China..
    Tong, Weijun
    Yangtze Opt Fiber & Cable Joint Stock Ltd Co YOFC, Wuhan, Hubei, Peoples R China..
    De Keulenaer, Timothy
    Univ Ghent, Imec, Spin Off IDLab, BiFAST, Ghent, Belgium..
    Torfs, Guy
    Univ Ghent, Imec, IDLab, Dept Informat Technol, Ghent, Belgium..
    Bauwelinck, Johan
    Univ Ghent, Imec, IDLab, Dept Informat Technol, Ghent, Belgium..
    Yin, Xin
    Univ Ghent, Imec, IDLab, Dept Informat Technol, Ghent, Belgium..
    Chen, Jiajia
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Spatial Division Multiplexing for Optical Data Center Networks2018Ingår i: 22ND INTERNATIONAL CONFERENCE ON OPTICAL NETWORK DESIGN AND MODELING (ONDM 2018) / [ed] Ruffini, M Tzanakaki, A Casellas, R Autenrieth, A MarquezBarja, JM, IEEE , 2018, s. 239-241Konferensbidrag (Refereegranskat)
    Abstract [en]

    Emerging mobile and cloud applications drive everincreasing capacity demands, particularly for short-reach optical communications, where low-cost and low-power solutions are highly required. Spatial division multiplexing (SDM) techniques provide a promising way to scale up the lane count per fiber, while reducing the number of fiber connections and patch cords, and hence simplifying cabling complexity. This talk will address challenges on both system and network levels, and report our recent development on SDM techniques for optical data center networks.

  • 20.
    Liu, Lige
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik. Beijing Inst Technol, Sch Phys, Beijing Key Lab, Nanophoton & Ultrafine Optoelect Syst, 5 South St Zhongguancun, Beijing 100081, Peoples R China.
    Deng, Luogen
    Beijing Inst Technol, Sch Phys, Beijing Key Lab, Nanophoton & Ultrafine Optoelect Syst, 5 South St Zhongguancun, Beijing 100081, Peoples R China..
    Huang, Sheng
    Beijing Inst Technol, Sch Mat Sci & Engn, 5 South St Zhongguancun, Beijing 100081, Peoples R China..
    Zhang, Pei
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik. Zhengzhou Univ Light Ind, Sch Elect & Informat Engn, Henan Key Lab Informat Based Elect Appliances, Zhengzhou 450002, Henan, Peoples R China.
    Linnros, Jan
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Zhong, Haizheng
    Beijing Inst Technol, Sch Mat Sci & Engn, 5 South St Zhongguancun, Beijing 100081, Peoples R China..
    Sychugov, Ilya
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Photodegradation of Organometal Hybrid Perovskite Nanocrystals: Clarifying the Role of Oxygen by Single-Dot Photoluminescence2019Ingår i: Journal of Physical Chemistry Letters, ISSN 1948-7185, E-ISSN 1948-7185, Vol. 10, nr 4, s. 864-869Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Photostability has been a major issue for perovskite materials. Understanding the photodegradation mechanism and suppressing it are of central importance for applications. By investigating single-dot photoluminescence spectra and the lifetime of MAPbX(3) (MA = CH3NH3+, X = Br, I) nanocrystals with quantum confinement under different conditions, we identified two separate pathways in the photodegradation process. The first is the oxygen-assisted light-induced etching process (photochemistry). The second is the light-driven slow charge-trapping process (photophysics), taking place even in oxygen-free environment. We clarified the role of oxygen in the photodegradation process and show how the photoinduced etching can be successfully suppressed by OSTE polymer, preventing an oxygen-assisted reaction.

  • 21.
    Liu, Lige
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik. State Key Laboratory for Mesoscopic Physics, Collaborative Innovation Center of Quantum Matter, School of Physics, Peking University, Beijing, 100871, China.
    Zhao, R.
    Xiao, C.
    Zhang, F.
    Pevere, Federico
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Material- och nanofysik.
    Shi, K.
    Huang, H.
    Zhong, H.
    Sychugov, Ilya
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Size-Dependent Phase Transition in Perovskite Nanocrystals2019Ingår i: Journal of Physical Chemistry Letters, ISSN 1948-7185, E-ISSN 1948-7185, Vol. 10, nr 18, s. 5451-5457Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The complex structure of halide and oxide perovskites strongly affects their physical properties. Here, the effect of dimensions reduced to the nanoscale has been investigated by a combination of single-dot optical experiments with a phase transition theory. Methylammonium lead bromide (CH3NH3PbBr3) nanocrystals with two average particle sizes of ∼2 and ∼4 nm with blue and green photoluminescence, respectively, were spectrally and temporally probed on a single-particle level from 5 to 295 K. The results show that the abrupt blue shift of the photoluminescence spectra and lifetimes at ∼150 K can be attributed to the cubic-to-tetragonal phase transition in the large 4 nm nanocrystals, while this phase transition is completely absent for the small 2 nm particles in the investigated temperature range. Theoretical calculations based on Landau theory reveal a strong size-dependent effect on temperature-induced phase transitions in individual CH3NH3PbBr3 nanocrystals, corroborating experimental observations. This effect should be considered in structure-property analysis of ultrasmall perovskite crystals.

  • 22.
    Liu, Lige
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik. Peking Univ, Sch Phys, Collaborat Innovat Ctr Quantum Matter, State Key Lab Mesoscop Phys, Beijing 100871, Peoples R China..
    Zhao, Ru
    Beijing Inst Technol, Sch Mat Sci & Engn, 5 South St Zhongguancun, Beijing 100081, Peoples R China.;Beijing Inst Technol, Adv Res Inst Multidisciplinary Sci, 5 South St Zhongguancun, Beijing 100081, Peoples R China..
    Xiao, Changtao
    Beijing Inst Technol, Sch Mat Sci & Engn, 5 South St Zhongguancun, Beijing 100081, Peoples R China.;Yangtze River Storage Technol Co Ltd, Gaoxin Fourth Rd, Wuhan 430000, Hubei, Peoples R China..
    Zhang, Feng
    Beijing Inst Technol, Sch Mat Sci & Engn, 5 South St Zhongguancun, Beijing 100081, Peoples R China.;Tsinghua Univ, Dept Chem, Beijing 100084, Peoples R China..
    Pevere, Federico
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Material- och nanofysik.
    Shi, Kebin
    Peking Univ, Sch Phys, Collaborat Innovat Ctr Quantum Matter, State Key Lab Mesoscop Phys, Beijing 100871, Peoples R China..
    Huang, Houbing
    Beijing Inst Technol, Sch Mat Sci & Engn, 5 South St Zhongguancun, Beijing 100081, Peoples R China.;Beijing Inst Technol, Adv Res Inst Multidisciplinary Sci, 5 South St Zhongguancun, Beijing 100081, Peoples R China..
    Zhong, Haizheng
    Beijing Inst Technol, Sch Mat Sci & Engn, 5 South St Zhongguancun, Beijing 100081, Peoples R China..
    Sychugov, Ilya
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Using Mechanical Stress to Investigate the Rashba Effect in Organic-Inorganic Hybrid Perovskites2019Ingår i: Journal of Physical Chemistry Letters, ISSN 1948-7185, E-ISSN 1948-7185, Vol. 10, nr 18, s. 5451-5457Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Organic-inorganic hybrid perovskites simultaneously possess strong spin- orbit coupling (SOC) and structure inversion asymmetry, establishing a Rashba effect to influence light emission and photovoltaics. Here, we use mechanical bending as a convenient approach to investigate the Rashba effect through SOC in perovskite (MAPbI(3-x)Cl(x)) films by elastically deforming grains. It is observed that applying a concave bending can broaden the line shape of the magnetophotocurrent, increasing the internal magnetic parameter B-0 from 121 to 205 mT, which indicates an enhancement on SOC. Interestingly, the PL lifetime is found to be enlarged from 9.9 to 14.8 ns under this bending, which suggests that introducing compressive strain can essentially increase the Rashba effect through SOC, leading to an increase upon indirect band transition. Furthermore, the PL peak associated with the Rashba effect is shifted from 776 to 780 nm under this mechanical bending. Therefore, mechanical bending provides a convenient experimental method to approach the Rashba effect in hybrid perovskites.

  • 23.
    Loiko, Pavel
    et al.
    ITMO Univ, 49 Kronverkskiy Pr, St Petersburg 197101, Russia..
    Maria Serres, Josep
    Univ Rovira & Virgili, Fis & Cristallog Mat & Nanomat FiCMA FiCNA, Campus Sescelades,C Marcelli Domingo S-N, E-43007 Tarragona, Spain..
    Delekta, Szymon Sollami
    KTH, Skolan för informations- och kommunikationsteknik (ICT).
    Kifle, Esrom
    Univ Rovira & Virgili, Fis & Cristallog Mat & Nanomat FiCMA FiCNA, Campus Sescelades,C Marcelli Domingo S-N, E-43007 Tarragona, Spain..
    Mateos, Xavier
    Univ Rovira & Virgili, Fis & Cristallog Mat & Nanomat FiCMA FiCNA, Campus Sescelades,C Marcelli Domingo S-N, E-43007 Tarragona, Spain.;Max Born Inst Nonlinear Opt & Short Pulse Spect, 2A Max Born Str, D-12489 Berlin, Germany..
    Baranov, Alexander
    ITMO Univ, 49 Kronverkskiy Pr, St Petersburg 197101, Russia..
    Aguilo, Magdalena
    Univ Rovira & Virgili, Fis & Cristallog Mat & Nanomat FiCMA FiCNA, Campus Sescelades,C Marcelli Domingo S-N, E-43007 Tarragona, Spain..
    Diaz, Francesc
    Univ Rovira & Virgili, Fis & Cristallog Mat & Nanomat FiCMA FiCNA, Campus Sescelades,C Marcelli Domingo S-N, E-43007 Tarragona, Spain..
    Griebner, Uwe
    Max Born Inst Nonlinear Opt & Short Pulse Spect, 2A Max Born Str, D-12489 Berlin, Germany..
    Petrov, Valentin
    Max Born Inst Nonlinear Opt & Short Pulse Spect, 2A Max Born Str, D-12489 Berlin, Germany..
    Popov, Sergei
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Li, Jiantong
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Elektronik, Integrerade komponenter och kretsar.
    Östling, Mikael
    KTH, Skolan för informations- och kommunikationsteknik (ICT).
    Inkjet-Printing of Graphene Saturable Absorbers for similar to 2 mu m Bulk and Waveguide Lasers2017Ingår i: 2017 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO), IEEE , 2017Konferensbidrag (Refereegranskat)
    Abstract [en]

    We report on inkjet-printing of graphene saturable absorbers (SAs) suitable for passive Q-switching of similar to 2-mu m bulk and waveguide lasers. Using graphene-SA in a microchip Tm:KLu(WO4)(2) laser, 1.2 mu J/136 ns pulses are generated at 1917 nm.

  • 24.
    Lourdudoss, Sebastian
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Bowers, John E.
    Univ Calif Santa Barbara, Inst Energy Efficiency, Santa Barbara, CA 93106 USA..
    Jagadish, Chennupati
    Australian Natl Univ, Res Sch Phys & Engn, Dept Elect Mat Engn, Canberra, ACT 2601, Australia..
    SEMICONDUCTORS AND SEMIMETALS Future Directions in Silicon Photonics Preface2019Ingår i: FUTURE DIRECTIONS IN SILICON PHOTONICS / [ed] Lourdudoss, S Bowers, JE Jagadish, C, ELSEVIER ACADEMIC PRESS INC , 2019, s. XV-XVIIIKapitel i bok, del av antologi (Refereegranskat)
  • 25.
    Lourdudoss, Sebastian
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Chen, R. T.
    Jagadish, C.
    Preface2018Ingår i: Semiconductors and Semimetals, Academic Press Inc. , 2018, s. ix-xiKapitel i bok, del av antologi (Refereegranskat)
  • 26.
    Lu, Longhui
    et al.
    Huazhong Univ Sci & Technol, Sch Opt & Elect Informat, Wuhan 430074, Hubei, Peoples R China..
    Liu, Deming
    Huazhong Univ Sci & Technol, Sch Opt & Elect Informat, Wuhan 430074, Hubei, Peoples R China..
    Yan, Max
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Zhang, Minming
    Huazhong Univ Sci & Technol, Sch Opt & Elect Informat, Wuhan 430074, Hubei, Peoples R China.;Wuhan Natl Lab Optoelect, Wuhan 430074, Hubei, Peoples R China..
    Subwavelength adiabatic multimode Y-junctions2019Ingår i: Optics Letters, ISSN 0146-9592, E-ISSN 1539-4794, Vol. 44, nr 19, s. 4729-4732Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Adiabatic multimode Y-junctions are extensively used for the design of multimode silicon photonics devices due to their straightforward principle in achieving mode splitting and manipulation. However, experimentally, the limited feature size achievable by lithography can greatly deteriorate the adiabatic branching property and result in large excess loss and crosstalk. Here, we propose a branch structure consisting of a circular-hole-based chirped subwavelength slot. By optimizing the holes' radii and positions under our fabrication constraint, we designed and experimentally demonstrated both symmetric and asymmetric approximately adiabatic four-mode Y-junctions with excellent performance close to ideal Y-junctions over a broad wavelength span. Such junctions are compact, CMOS-compatible, exhibit a relatively large fabrication tolerance, and could be extended for more modes; hence they can be potentially deployed for mode-division multiplexing silicon-photonic systems.

  • 27.
    Lu, Xingyuan
    et al.
    Soochow Univ, Sch Phys Sci & Technol, Suzhou 215006, Peoples R China..
    Zhao, Chengliang
    Soochow Univ, Sch Phys Sci & Technol, Suzhou 215006, Peoples R China..
    Shao, Yifeng
    Delft Univ Technol, Opt Res Grp, NL-2628 CH Delft, Netherlands..
    Zeng, Jun
    Soochow Univ, Sch Phys Sci & Technol, Suzhou 215006, Peoples R China..
    Konijnenberg, Sander
    Delft Univ Technol, Opt Res Grp, NL-2628 CH Delft, Netherlands..
    Zhu, Xinlei
    Soochow Univ, Sch Phys Sci & Technol, Suzhou 215006, Peoples R China..
    Popov, Sergei
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Urbach, H. Paul
    Delft Univ Technol, Opt Res Grp, NL-2628 CH Delft, Netherlands..
    Cai, Yangjian
    Soochow Univ, Sch Phys Sci & Technol, Suzhou 215006, Peoples R China.;Shandong Normal Univ, Sch Phys & Elect, Shandong Prov Engn & Tech Ctr Light Manipulat, Jinan 250014, Shandong, Peoples R China.;Shandong Normal Univ, Sch Phys & Elect, Shandong Prov Key Lab Opt & Photon Device, Jinan 250014, Shandong, Peoples R China..
    Phase detection of coherence singularities and determination of the topological charge of a partially coherent vortex beam2019Ingår i: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 114, nr 20, artikel-id 201106Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In the theory of partial coherence, coherence singularities can occur in the spectral degree of coherence (SDOC): in case the fields at two different points are completely uncorrelated, the phase of the SDOC is undefined. For a partially coherent vortex beam, the detection of coherence singularities is linked to the measurement of topological charge, whose magnitude equals the number of ring dislocations in its far field amplitude. However, the phase distribution of coherence singularities is rarely mentioned in the literature and the amplitude distribution can hardly reflect the sign of topological charge. In this letter, we present a phase-analysis method for measuring the coherence singularities by introducing a movable perturbation at a certain point in an illumination window of a finite size. Using the proposed method, we measure experimentally the coherence singularities of a partially coherent vortex beam in the focal plane. From the results, the magnitude and sign of the topological charge can be determined simultaneously from the phase distribution of the coherence singularities. Our results can find application in information transmission.

  • 28.
    Lu, Yang
    et al.
    KTH.
    Agrell, Erik
    Chalmers Univ Technol, Dept Elect Engn, Gothenburg, Sweden..
    Pang, Xiaodan
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Ozolins, Oskars
    RISE Acreo AB, Networking & Transmiss Lab, Kista, Sweden..
    Hong, Xuezhi
    KTH.
    Lin, Rui
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Cheng, Yuxin
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Udalcovs, Aleksejs
    RISE Acreo AB, Networking & Transmiss Lab, Kista, Sweden..
    Popov, Sergei
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Jacobsen, Gunnar
    RISE Acreo AB, Networking & Transmiss Lab, Kista, Sweden..
    Chen, Jiajia
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Matrix Receiving Scheme Supporting Arbitrary Multiple-Wavelength Reception for Optical Interconnects2017Ingår i: 43RD EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION (ECOC 2017), IEEE , 2017Konferensbidrag (Refereegranskat)
    Abstract [en]

    An arbitrary multiple-wavelength reception scheme using only a few fixed-wavelength filters is proposed for optical interconnects. Filter matrices design based on error-control coding theory is devised. The feasibility of the proposed scheme is demonstrated in a four-wavelength reception experiment.

  • 29.
    Lu, Yang
    et al.
    Hangzhou Dianzi Univ, Coll Commun Engn, Hangzhou, Zhejiang, Peoples R China..
    Agrell, Erik
    Chalmers Univ Technol, Dept Elect Engn, Gothenburg, Sweden..
    Pang, Xiaodan
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab). RISE Acreo AB, Networking & Transmiss Lab, Kista, Sweden..
    Ozolins, Oskars
    RISE Acreo AB, Networking & Transmiss Lab, Kista, Sweden..
    Hong, Xuezhi
    South China Normal Univ, ZJU SCNU Joint Res Ctr Photon, Guangzhou 510006, Guangdong, Peoples R China..
    Lin, Rui
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Cheng, Yuxin
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Udalcovs, Aleksejs
    RISE Acreo AB, Networking & Transmiss Lab, Kista, Sweden..
    Popov, Sergei
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Jacobsen, Gunnar
    RISE Acreo AB, Networking & Transmiss Lab, Kista, Sweden..
    Chen, Jiajia
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Multi-channel collision-free reception for optical interconnects2018Ingår i: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 26, nr 10, s. 13214-13222Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A multi channel reception scheme that allows each node to receive an arbitrary set of wavelengths simultaneously (i.e., collision-free) is proposed for optical interconnects. The proposed scheme only needs to use a few receivers and fixed-wavelength filters that are designed based on error-control coding theory. Experiments with up to four channel collision-free reception units are carried out to demonstrate the feasibility of the proposed scheme.

  • 30.
    Marcinkevičius, Saulius
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Mensi, Mounir
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Ivanov, Ruslan
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Kuritzky, Leah Y.
    DenBaars, Steven P.
    Nakamura, Shuji
    Speck, James S.
    Multimode scanning near-field photoluminescence spectroscopy of InGaN quantum wells2018Ingår i: 2018 IEEE RESEARCH AND APPLICATIONS OF PHOTONICS IN DEFENSE CONFERENCE (RAPID), IEEE , 2018, s. 93-95Konferensbidrag (Refereegranskat)
    Abstract [en]

    Multimode scanning near-field photoluminescence spectroscopy was developed and applied to study carrier localization and dynamics in m-plane InGaN quantum wells. The study showed that localized hole states maintain properties of extended bands, radiative and nonradiative carrier lifetimes are spatially nonuniform, and hole diffusion is anisotropic.

  • 31.
    Marinins, Aleksandrs
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Udalcovs, A.
    Ozolins, O.
    Pang, X.
    Veinot, J.
    Jacobsen, G.
    Sychugov, Ilya
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Linnros, Jan
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Popov, Sergei
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    All-optical intensity modulation in polymer waveguides doped with si quantum dots2018Ingår i: Optics InfoBase Conference Papers, Optical Society of America, 2018Konferensbidrag (Refereegranskat)
    Abstract [en]

    We demonstrate all-optical intensity modulation in integrated PMMA optical waveguides doped with silicon quantum dots. The 1550 nm probe signal is absorbed by free carriers excited in silicon quantum dots with 405 nm pump light.

  • 32. Navarro, J. R.
    et al.
    Udalcovs, A.
    Pang, Xiaodan
    KTH, Skolan för informations- och kommunikationsteknik (ICT).
    Ozolins, O.
    Kakkar, Aditya
    KTH, Skolan för teknikvetenskap (SCI).
    Schatz, Richard
    KTH, Skolan för teknikvetenskap (SCI).
    Nordwall, F.
    Popov, Sergei
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Jacobsen, G.
    High phase noise tolerant circular-64QAM with efficient phase recovery for coherent optical systems2017Ingår i: Optics InfoBase Conference Papers, OSA - The Optical Society , 2017Konferensbidrag (Refereegranskat)
    Abstract [en]

    We experimentally demonstrate the significant phase noise tolerance increase of 28Gbaud circular-64QAM constellations against its square-64QAM counterpart with a novel, low complexity and high-performance phase recovery scheme employing only 8 test phases.

  • 33.
    Omanakuttan, Giriprasanth
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Epitaxial III-V/Si heterojunctions for photonic devices.2019Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [sv]

    Monolitisk integrering av III-V material på kisel är av stort intresse för billiga och effektiva elektroniska-fotoniska komponenter och tandemsolceller på kisel. Detta är en stor utmaning på grund av defektbildning i de heteroepitaxiellt odlade materialen som orsakas av skillnaden i gitterkonstant, skillnaden i termisk expansion och olika polaritet. Detta arbete åstadkommer epitaxiella lager av III-V material på kisel med hög kvalité genom epitaxiell lateral överväxt (ELOG) och korrugerad epitaxiell lateral överväxt (CELOG) utförd i hydridgasfasepitaxi (HVPE). Vi demonstrerar både elektroluminiscens från multi-kvantbrunnstrukturer (MQW) odlade på ELOG-framställda InP/Si-substrat och fotodiodbeteende från n-InP/p-Si material framställt av CELOG. Denna avhandling fokuserar även på utförlig karaktärisering av InP/Si och GaxIn1-xP/Si framställd med CELOG, bestående av röntgendiffraktion, (tidsupplöst) fotoluminiscens, Ramanspektroskopi, katodluminiscens, samt svep- och transmissionselektronmikroskopi.Ett heltäckande InP-lager har odlats på en 3” kiselskiva genom ELOG; InP/Si skivan har sedan använts som substrat till tillverkningen av en multi-kvantbrunnbaserad lysdiod med emission vid 1550 nm. Nämnvärt stark katodluminiscens observerades över alla områden på skivan, även de där MQW – tillverkningen skedde på InP som odlats direkt över grolagret. Trots att spontan emission uppnåddes så observerades inte stimulerad emission, vilket vi främst tillskriver den ojämna ytmorfologin efter odling av MQW. Mätningar vid transparensvillkor indikerar att det uppstår förstärkning i materialet, vilket visar på potential hos tekniken för tillverkning av laser på kiselsubstrat. Problem med en viss böjning av skivan under framställningsprocessen på grund av termisk stress måste också adresseras.CELOG av InP/Si resulterade i högkristallina InP lager med en abrupt och direktövergång fri från dislokationer till kiselsubstratet trots den 8% stora skillnaden mellan materialens gitterkonstant. Frånvaron av propagerande dislokationer i materialet indikerar att de defekter som ger upphov till dessa, vilka i sin tur orsakas av skillnaden i gitterkonstant, istället begränsas till övergången – en effekt som är typisk för heterostrukturer tillverkade genom wafer-bindning. Detta indikerar att CELOG metoden agerar som en epitaxiell wafer-bindning utförd vid odlingstemperaturen. CELOG användes för att tillverka en fotodiod av en n-InP/p-Si – heteroövergång som en konceptvalidering; dioden uppmätte en maxspänning på 180 mV (VOC), en högsta strömtäthet på 1.89 mA/cm2 samt en intern och extern kvantverkningsgrad på 6% respektive 4%. Trots den låga prestandan demonstrerar detta potential hos CELOG-metoden att användas till III-V/Si integration för applikationer inom solenergi.CELOG metoden har också använts för att demonstrera en direkt GaxIn1-xP/Si – övergång som är fri från dislokationer. Som en förstudie till detta har optimering av GaInP odlad på substrat av ELOG-mönstrad GaAs utförts. Den CELOG–framställda GaInP/Si-odlingen uppvisar riktningsberoende tillväxt och anisotropi i dess sammansättning. Stapelfel uppträder i GaInP/Si-övergången, men precis som för CELOG–InP/Si så bildas inga propagerande dislokationer. Vid övergången bildades ett ~1 nm tjockt atomiskt oordnade mellanlager. GaInP–lagren är fullständigt relaxerade och ingen stress har observerats trots den 4% stora skillnaden i gitterkonstant mellan lagren och substratet. Mätningar av sammansättningen hos GaInP– lagren med direktkontakt till kiselsubstratet utförda med transmissionselektronmikroskopi och fotoluminiscens överensstämmer med varandra.Vi drar slutsatsen att det finns förbättringsmöjligheter för ELOG och CELOG–processerna för att uppnå tillräckligt hög kvalité på lagren för komponenttillverkning. Vi har demonstrerat att CELOG–metoden är en allmän teknik som kan användas för att uppnå övergångar med hög kvalité i materialsystem som är termiskt och polärt missanpassade samt har olika gitterkonstanter. Det visar på att optimerade ELOG och CELOG–processer kan möjliggöra monolitisk integrering av III-V–material på kisel för kiselfotonik och kostnadseffektiva tandemsolceller med hög verkningsgrad.

  • 34.
    Omanakuttan, Giriprasanth
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Sun, Yan-Ting
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Reuterskiöld-Hedlund, Carl
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Elektronik, Integrerade komponenter och kretsar.
    Junesand, Carl
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Schatz, Richard
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Lourdudoss, Sebastian
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Paillard, Valerie
    Almae Technologies.
    Lelarge, François
    Almae Technologies.
    Browne, Jack
    Tyndall National Institute.
    Justice, John
    Tyndall National Institute.
    Corbett, Brian
    Tyndall National Institute.
    Electrically pumped 1.5 μm gain material on InP/SiManuskript (preprint) (Övrigt vetenskapligt)
  • 35.
    Omanakuttan, Giriprasanth
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Wang, Chengru
    Shanghai Jiao Tong University.
    Lourdudoss, Sebastian
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Xie, Chaoying
    Shanghai Jiao Tong University.
    Sun, Yan-Ting
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Composition and interface studies of GaxIn1-xP/Si heterojunctionManuskript (preprint) (Övrigt vetenskapligt)
  • 36.
    Oxenløwe, L. K.
    et al.
    Denmark.
    Jia, S.
    Denmark.
    Pang, X.
    Ozolins, O.
    Yu, X.
    China.
    Hu, H.
    Guan, P.
    Da Ros, F.
    Popov, Sergei
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Jacobsen, G.
    Galili, M.
    Denmark.
    Zibar, D.
    Denmark.
    Morioka, T.
    Denmark.
    100s gigabit/s THz communication2018Ingår i: Optics InfoBase Conference Papers, OSA - The Optical Society , 2018Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper gives an overview of recent progress on the topic of using around 0.4 THz carriers for communications. Experimental demonstrations will be described, and concepts and pros & cons of various system-platforms discussed.

  • 37. Ozolins, O.
    et al.
    Da Ros, F.
    Cristofori, V.
    Pang, Xiaodan
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Udalcovs, A.
    Schatz, R.
    Oxenløwe, L. K.
    Popov, Sergei
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Jacobsen, G.
    Peucheret, C.
    Impact of phase-filtering on optical spectral reshaping with microring resonators for directly-modulated 4-PAM signals2018Ingår i: Optics InfoBase Conference Papers, Optical Society of America, 2018Konferensbidrag (Refereegranskat)
    Abstract [en]

    We investigate microring resonator (MRRs)-based optical spectral reshaping for directly-modulated 4-PAM signals. The phase-filtering of MRR, and consequent dispersion added to the signal, yields 120% reach increase compared to the 95% of amplitude-only filtering.

  • 38. Ozolins, O.
    et al.
    Pang, Xiaodan
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Udalcovs, A.
    Lin, Rui
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Van Kerrebrouck, J.
    Gan, L.
    Zhang, Lu
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Tang, M.
    Fu, S.
    Schatz, Richard
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Westergren, Urban
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Jacobsen, G.
    Liu, D.
    Tong, W.
    Torfs, G.
    Bauwelinck, J.
    Chen, Jiajia
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Popov, Sergei
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Yin, X.
    7×149 Gbit/s PAM4 transmission over 1 km multicore fiber for short-reach optical interconnects2018Ingår i: Optics InfoBase Conference Papers, Optics Info Base, Optical Society of America, 2018Konferensbidrag (Refereegranskat)
    Abstract [en]

    We transmit 80 Gbaud/λ/core PAM4 signal enabled by 1.55 μm EML over 1 km 7-core fiber. The solution achieves single-wavelength and single-fiber 1.04 Tbit/s post-FEC transmission enhancing bandwidth-density for short-reach optical interconnects.

  • 39.
    Ozolins, O.
    et al.
    RISE Acreo, Kista, Sweden..
    Pang, Xiaodan
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab). RISE Acreo, Kista, Sweden.
    Udalcovs, A.
    RISE Acreo, Kista, Sweden..
    Zhang, Lu
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Schatz, Richard
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Westergren, Urban
    Jacobsen, G.
    RISE Acreo, Kista, Sweden..
    Popov, Sergei
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Chen, Jiajia
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Short Reach Optical Interconnects with Single Externally Modulated Laser Operated in C-Band2018Ingår i: 2018 20TH ANNIVERSARY INTERNATIONAL CONFERENCE ON TRANSPARENT OPTICAL NETWORKS (ICTON) / [ed] Jaworski, M Marciniak, M, Institute of Electrical and Electronics Engineers (IEEE), 2018Konferensbidrag (Refereegranskat)
  • 40. Ozolins, O.
    et al.
    Udalcovs, A.
    Pang, Xiaodan
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Lin, Rui
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Djupsjöbacka, A.
    Mårtensson, J.
    Fröjdh, K.
    Gan, L.
    Tang, M.
    Fu, S.
    Schatz, Richard
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Westergren, Urban
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Liu, D.
    Tong, W.
    Chen, Jiajia
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Popov, Sergei
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Jacobsen, G.
    112 Gbps/λ PAM4 inter-DCI with continuous-fiber Bragg grating based dispersion compensators2018Ingår i: Optics InfoBase Conference Papers, OSA - The Optical Society , 2018Konferensbidrag (Refereegranskat)
    Abstract [en]

    We demonstrate 56 Gbaud/λ PAM4 inter - data center interconnects over 81 km single core single mode fiber and 33.6 km 7-core single mode fiber with continuous-fiber Bragg grating based chromatic dispersion compensators covering C-band.

  • 41.
    Ozolins, Oskars
    et al.
    RISE Acreo AB, Networking & Transmiss Lab, Kista, Sweden..
    Pang, Xiaodan
    RISE Acreo AB, Networking & Transmiss Lab, Kista, Sweden.;KTH Royal Inst Technol, Sch ICT, Stockholm, Sweden.;KTH Royal Inst Technol, Sch SCI, Stockholm, Sweden..
    Udalcovs, Aleksejs
    RISE Acreo AB, Networking & Transmiss Lab, Kista, Sweden..
    Schatz, Richard
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Westergren, Urban
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Rodrigo Navarro, Jaime
    Kakkar, Aditya
    KTH.
    Nordwall, Fredrik
    Tektronix AB, Stockholm, Sweden..
    Engenhardt, Klaus M.
    Tektronix GmbH, Stuttgart, Germany..
    Chen, Jiajia
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Popov, Sergei
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Jacobsen, Gunnar
    RISE Acreo AB, Networking & Transmiss Lab, Kista, Sweden..
    100 Gbaud 4PAM Link for High Speed Optical Interconnects2017Ingår i: 43RD EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION (ECOC 2017), IEEE , 2017Konferensbidrag (Refereegranskat)
    Abstract [en]

    We demonstrate 100 Gbaud 4PAM transmission over 400 meters SMF with monolithically integrated 1550 nm DFB-TWEAM having 100 GHz 3-dB bandwidth with 2 dB ripple. We evaluate its capabilities to enable two lanes 400 GbE client-side links for optical interconnects.

  • 42.
    Pang, Xiaodan
    et al.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Ozolins, O.
    RISE Acreo AB, NETLAB Networking & Transmiss Lab, Isafjordsgatan 22, S-16440 Kista, Sweden..
    Navarro, Julien R. G.
    Udalcovs, A.
    RISE Acreo AB, NETLAB Networking & Transmiss Lab, Isafjordsgatan 22, S-16440 Kista, Sweden..
    Kakkar, Aditya
    KTH, Skolan för elektroteknik och datavetenskap (EECS).
    Lin, Rui
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Schatz, Richard
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik. KTH Royal Inst Technol, Isafjordsgatan 22, S-16440 Kista, Sweden..
    Tang, M.
    Huazhong Univ Sci & Technol, Wuhan, Hubei, Peoples R China..
    Fu, S.
    Huazhong Univ Sci & Technol, Wuhan, Hubei, Peoples R China..
    Liu, D.
    Huazhong Univ Sci & Technol, Wuhan, Hubei, Peoples R China..
    Jacobsen, G.
    RISE Acreo AB, NETLAB Networking & Transmiss Lab, Isafjordsgatan 22, S-16440 Kista, Sweden..
    Popov, Sergei
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Chen, Jiajia
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Low-Complexity Digital Signal Processing Techniques to Enable Coherent Optical Systems for Metro and Access networks2018Ingår i: 23RD OPTO-ELECTRONICS AND COMMUNICATIONS CONFERENCE (OECC2018), IEEE , 2018Konferensbidrag (Refereegranskat)
    Abstract [en]

    We summarize our recent research works on enabling coherent optical transmission systems for metro and access networks with low-complexity digital signal processing techniques, focusing on reduction of laser linewidth requirement with efficient carrier phase recovery.

  • 43.
    Pang, Xiaodan
    et al.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Ozolins, O.
    Zhang, L.
    Schatz, Richard
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Udalcovs, A.
    Storck, Joakim
    KTH.
    Maisons, G.
    Carras, M.
    Xiao, S.
    Jacobsen, G.
    Popov, Sergei
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Chen, Jiajia
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Lourdudoss, Sebastian
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    4 Gbps PAM-4 and DMT Free Space Transmission using a 4.65-pm Quantum Cascaded Laser at Room Temperature2017Ingår i: European Conference on Optical Communication, ECOC, Institute of Electrical and Electronics Engineers Inc. , 2017, s. 1-3Konferensbidrag (Refereegranskat)
    Abstract [en]

    We experimentally demonstrate 4Gbps PAM-4 and DMT transmissions using a quantum cascaded laser (QCL) emitting at mid-wavelength infrared of 4.65μm and a commercial infrared photovoltaic detector. The QCL is directly modulated and operated at room temperature with Peltier Cooling. 

  • 44.
    Pang, Xiaodan
    et al.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Ozolins, Oskars
    RISE Acreo AB, Networking & Transmiss Lab, Kista, Sweden..
    Zhang, Lu
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Schatz, Richard
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Udalcovs, Aleksejs
    RISE Acreo AB, Networking & Transmiss Lab, Kista, Sweden..
    Storck, Joakim
    KTH, Skolan för elektroteknik och datavetenskap (EECS).
    Maisons, Gregory
    mirSense, Ctr Integrat Nanolnnov, F-91120 Palaiseau, France..
    Carras, Mathieu
    mirSense, Ctr Integrat Nanolnnov, F-91120 Palaiseau, France..
    Xiao, Shilin
    Shanghai Jiao Tong Univ, State Key Lab Adv Opt Commun Syst & Networks, Shanghai, Peoples R China..
    Jacobsen, Gunnar
    RISE Acreo AB, Networking & Transmiss Lab, Kista, Sweden..
    Popov, Sergei
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Chen, Jiajia
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Lourdudoss, Sebastian
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    4 Gbps PAM-4 and DMT Free Space Transmission using A 4.65-mu m Quantum Cascaded Laser at Room Temperature2017Ingår i: 43RD EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION (ECOC 2017), IEEE , 2017Konferensbidrag (Refereegranskat)
    Abstract [en]

    We experimentally demonstrate 4Gbps PAM-4 and DMT transmissions using a quantum cascaded laser (QCL) emitting at mid-wavelength infrared of 4.65-mu m and a commercial infrared photovoltaic detector. The QCL is directly modulated and operated at room temperature with Peltier Cooling.

  • 45.
    Pang, Xiaodan
    et al.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab). DLab., INTEC, Ghent University - Imec, Gent, BelgiumDLab., INTEC, Ghent University - Imec, Gent, Belgium.
    Van Kerrebrouck, J.
    Ozolins, O.
    Lin, R.
    Udalcovs, A.
    Zhang, Lu
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Spiga, S.
    Amann, M. C.
    Van Steenberge, G.
    Gan, L.
    Tang, M.
    Fu, S.
    Schatz, R.
    Jacobsen, G.
    Popov, Sergei
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Liu, D.
    Tong, W.
    Torfs, G.
    Bauwelinck, J.
    Yin, X.
    Chen, Jiajia
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    7×100 Gbps PAM-4 transmission over 1-km and 10-km single mode 7-core fiber using 1.5-μm SM-VCSEL2018Ingår i: 2018 Optical Fiber Communications Conference and Exposition, OFC 2018 - Proceedings, Institute of Electrical and Electronics Engineers (IEEE), 2018, s. 1-3Konferensbidrag (Refereegranskat)
    Abstract [en]

    100 Gbps/λ/core PAM-4 transmission is successfully demonstrated over 1-km and 10-km single mode 7-core fiber links, enabled by directly modulated 1.5-μm single mode VCSEL of 23 GHz modulation bandwidth with pre- and post-digital equalizations. © 2018 OSA.

  • 46.
    Pang, Xiaodan
    et al.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Van Kerrebrouck, J.
    Belgium.
    Ozolins, O.
    Lin, Rui
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Udalcovs, A.
    Zhang, Lu
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Spiga, S.
    Germany.
    Amann, M. C.
    Germany.
    Van Steenberge, G.
    Belgium.
    Gan, L.
    China.
    Tang, M.
    China.
    Fu, S.
    China.
    Schatz, Richard
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Jacobsen, G.
    Popov, Sergei
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Liu, D.
    China.
    Tong, W.
    China.
    Torfs, G.
    Belgium.
    Bauwelinck, J.
    Belgium.
    Yin, X.
    Belgium.
    Chen, Jiajia
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    7×100 Gbps PAM-4 transmission over 1-km and 10-km single mode 7-core fiber using 1.5-μm SM-VCSEL2018Ingår i: Optics InfoBase Conference Papers, Optical Society of America, 2018Konferensbidrag (Refereegranskat)
    Abstract [en]

    100 Gbps/λ/core PAM-4 transmission is successfully demonstrated over 1-km and 10- km single mode 7-core fiber links, enabled by directly modulated 1.5-μm single mode VCSEL of 23 GHz modulation bandwidth with pre- and post- digital equalizations.

  • 47.
    Pang, Xiaodan
    et al.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Van Kerrebrouck, J.
    Belgium.
    Ozolins, O.
    Sweden.
    Lin, Rui
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Udalcovs, A.
    Sweden.
    Zhang, Lu
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Spiga, S.
    Germany.
    Amann, M. C.
    Germany.
    Van Steenberge, G.
    Belgium.
    Gan, L.
    China.
    Tang, M.
    China.
    Fu, S.
    China.
    Schatz, Richard
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Jacobsen, G.
    Sweden.
    Popov, Sergei
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Liu, D.
    China.
    Tong, W.
    China.
    Torfs, G.
    Belgium.
    Bauwelinck, J.
    Belgium.
    Yin, X.
    Belgium.
    Chen, Jiajia
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    High-speed SDM interconnects with directly-modulated 1.5-μm VCSEL enabled by low-complexity signal processing techniques2018Ingår i: Optics InfoBase Conference Papers, OSA - The Optical Society , 2018Konferensbidrag (Refereegranskat)
    Abstract [en]

    We report on our recent work in supporting up to 100 Gbps/λ/core transmissions with a directly modulated 1.5-μm single mode VCSEL and multicore fiber, enabled by low-compleixty pre- and post- digital equalizations.

  • 48.
    Pang, Xiaodan
    et al.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab). Infinera, Fredsborgsgatan 24, Stockholm, SE-117 43, Sweden.
    Zhang, Lu
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Ozolins, Oskars
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Udalcovs, A.
    Lin, Rui
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Schats, Richard
    KTH.
    Xiao, S.
    Hu, W.
    Popov, Sergei
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Jacobsen, Gunnar
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Chen, Jiajia
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Key technologies to enable terabit-scale digital radio-over-fiber systems2019Ingår i: Broadband Access Communication Technologies XIII, SPIE - International Society for Optical Engineering, 2019, Vol. 10945, artikel-id 109450EKonferensbidrag (Refereegranskat)
    Abstract [en]

    With the approach of the 5G era, stringent requirements are imposed on the data transport solutions, including both of the supported transmission reach and the capacity. Radio-over-fiber technologies are considered to be promising candidates to cope with both aspects, owing to the low-loss and broad-bandwidth nature of the optical fibers. Meanwhile with such optical transport solutions, signals can be collected from the distributed remote radio sites and processed in a centralized manner. In this report, we target on the digital radio-over-fiber systems, and discuss about several key technologies, focusing on the aspects of coding and transmission, which could potentially enable terabit-scale data transport.

  • 49.
    Pevere, Federico
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Optical Properties of Single Silicon Quantum Dots2018Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    For over 60 years silicon (Si) has dominated the semiconductor microelectronics industry mainly due to its abundance and good electrical and material properties. The advanced processing technology of Si has made it the workhorse for photovoltaics industry as well. However, this material has also a big drawback: it is an indirect-bandgap semiconductor in its bulk form, hence an inefficient light emitter. This has hindered the silicon photonics revolution envisioned in 1980s, where photons were thought to replace electrons inside computer chips.

    In parallel with the exponential scaling of Si transistor's size over the years, the discovery of quantum phenomena at the nanoscale raised new hopes for this semiconductor. In the 1990s bright luminescence from nanostructured porous Si was demonstrated claiming the quantum confinement effect as origin of the emission. Since then, an intense research activity has been focused on Si quantum dots (Si-QDs) due to their potential use as abundant and non-toxic light emitters. More precisely, they could be used as fluorescent biolabels in biomedicine, as light-emitting phosphors in e.g. TV screens or as down-converters in luminescent solar concentrators. Nevertheless, in order to realize such applications, it is necessary not only to improve the fabrication of Si-QDs but also to gain a better understanding of their photo-physics. Among different types of optical measurements, those performed at the single-dot level are free of sample inhomogeneities, hence more accurate for a correct physical description.

    This doctoral thesis presents a study of the optical properties of single Si-QDs of different type: encapsulated in an oxide matrix, capped with ligands or covered by a thin passivation layer. The homogeneous photoluminescence (PL) linewidth is found to strongly depend on the type of embedding matrix, being narrower for less rigid ones. A record resolution-limited linewidth of ~200 μeV is measured at low temperatures whereas room-temperature values can even compete with direct-bandgap QDs like CdSe. Such narrow PL lines exhibit intensity saturation at high excitation fluxes without any indication of emission from multiexciton states, suggesting the presence of fast non-radiative Auger recombination. Characteristic Auger-related lifetimes extracted from power-dependent decays show a variation from dot-to-dot and confirm the low biexciton quantum efficiency.

    For the first time, the absorption curve of single Si-QDs is probed by means of photoluminescence excitation in the range 2.0-3.5 eV. A step-like structure is found which depends on the nanocrystal shape considered and agrees well with simulations of the exciton level structure. Rod-like Si-QDs can exhibit ~50 times higher absorption than spherical-like ones due to local field effects and enhanced optical transitions. In contrast with previous studies, evidence of a direct-bandgap red-shift for small Si-QDs is missing at the single dot level, in agreement with atomistic calculations.

    Low-temperature PL decay measurements reveal no triplet-like emission lines, but two ~μs decay constants appearing at low temperatures. They suggest presence of a temperature-dependent fast blinking process based on trapping/detrapping of carriers in the oxide matrix, leading to delayed emission. The proposed model allows to extract characteristic trapping/de-trapping rates for Si-QDs featuring mono-exponential blinking statistics. From PL saturation curves, ligand-passivated Si-QDs do not exhibit such detrimental phenomenon, in agreement with the proposed model.

    Last, Si-QDs demonstrate to be very hard against ~10 keV X-ray radiation, in contrast with CdSe-QDs whose PL quenching is correlated with a change in the blinking parameters. This property could be exploited for example in space applications, where radiation-hard materials are required.

    To conclude, the results achieved in this thesis will help to understand and engineer the properties of Si-QDs whose application potential has increased after several years of research both at the ensemble and at the single-dot level.

  • 50.
    Pevere, Federico
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    von Treskow, Carl
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Marino, Emanuele
    Van der Waals – Zeeman Institute, University of Amsterdam, The Netherlands.
    Anwar, Monib
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Bruhn, Benjamin
    Sychugov, Ilya
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Linnros, Jan
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    X-ray radiation hardness and influence on blinking in Si and CdSe quantum dots2018Ingår i: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 113, nr 25, artikel-id 253103Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We study the effect of X-ray irradiation on the photoluminescence (PL) efficiency and intermittency (blinking) of single Si/SiO2 and CdSe/CdZnS quantum dots (QDs). Our results show that the PL efficiency of Si nanocrystals is not significantly altered up to a cumulative fluence of 10(20) photons/m(2) (corresponding to similar to 300 kGy of absorbed dose in SiO2), while CdSe particles become completely dark already after a 17 times lower fluence. In both types of QDs, the statistical nature of blinking ON- and OFF-times remains unaltered: mono-exponential for Si and power-law for CdSe QDs. However, the evolution of the blinking parameters with absorbed dose depends on the choice of material. On average, both ON- and OFF-time constants do not vary in Si nanocrystals, highlighting their radiation hardness. Instead, the ON-time exponent increases while the OFF-time exponent decreases with the increasing dose for CdSe dots, confirming their efficiency quenching. Ensemble measurements did not show PL spectral changes neither indicated removal of surface ligands in irradiated CdSe dots. Thus, ionization-generated non-radiative centers in the core-shell system modify blinking of CdSe dots and eventually rapidly quench their emission, in contrast to robust Si/SiO2 nanocrystals. Our study is important for the future use of luminescent QDs in harsh environments, such as space, and the engineering of their blinking properties via ionizing radiation.

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