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  • 1.
    Aggerstam, Thomas
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Andersson, T.G.
    Holmström, Petter
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Jänes, Peter
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Liu, X. Y.
    Lourdudoss, Sebastian
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Thylén, Lars
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    GaN/AlN multiple quantum well structures grown by MBE on GaN templates for 1.55 mu m intersubband absorption2007Ingår i: Quantum Sensing and Nanophotonic Devices IV / [ed] Razeghi, M; Brown, GJ, 2007, Vol. 6479, s. 64791E-1-64791E-12Konferensbidrag (Refereegranskat)
    Abstract [en]

    We have used MBE to grow MQW structures on MOVPE GaN/sapphire templates. The MQW devices are intended for high speed intersubband electroabsorption modulator devices operating at 1.55-mu m. The GaN/AlN multiple quantum well material was systematically studied regarding the surface morphology, structural characterization and optical property by atomic force microscopy, X-ray diffraction and Fourier transform infrared spectroscopy, respectively. The intersubband resonance energy was also calculated considering many-body effects in n-type doped structures. The multiple quantum well structure showed superior performance in terms of linewidth when grown on GaN templates as compared on sapphire. GaN quantum well and AlN barriers with a thickness of 3.3 and 4.2 nm respectively resulted in FWHM of the intersubband absorption peak as low as 93 meV at an absorption energy of 700 meV. This is promising for intersubband modulator applications.

  • 2.
    Aggerstam, Thomas
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Electrumlaboratoriet, ELAB.
    Lourdudoss, Sebastian
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Electrumlaboratoriet, ELAB.
    Radamson, Henry H.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Electrumlaboratoriet, ELAB.
    Sjödin, Mikael
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Electrumlaboratoriet, ELAB.
    Lorenzini, P.
    CNRS-CHREA.
    Look, D.C.
    Semiconductor Research Center, Wright State University.
    Investigation of the interface properties of MOVPE grown AlGaN/GaN high electron mobility transistor (HEMT) structures on sapphire2006Ingår i: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 515, nr 2, s. 705-707Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We have developed a virtual GaN substrate on sapphire based on a two-step growth method. By optimizing the growth scheme for the virtual substrate we have improved crystal quality and reduced interface roughness. Our Al0.22Ga0.78N/GaN HEMT structure grown on the optimized semi-insulating GaN virtual substrate, exhibits Hall mobilities as high as 1720 and 7350 cm(2)/Vs and sheet carrier concentrations of 8.4 x 1012 and 10.0 x 1012 cm(-2) at 300 K and 20 K, respectively The presence of good AlGaN/GaN interface quality and surface morphology is also substantiated by X-Ray reflectivity and Atomic Force Microscopy measurements. A simplified transport model is used to fit the experimental Hall mobility.

  • 3.
    Aggerstam, Thomas
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Pinos, Andrea
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Marcinkevicius, Saulius
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik, Optik.
    Linnarsson, Margareta
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Lourdudoss, Sebastian
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Electron and hole capture cross-sections of Fe acceptors in GaN:Fe epitaxially grown on sapphire2007Ingår i: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 36, nr 12, s. 1621-1624Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Carrier trapping of Fe (3+)/Fe2+ deep acceptors in epitaxially grown GaN:Fe on sapphire was studied by time-resolved photoluminescence. For the investigated Fe doping levels on the order of 10(18) cm(-3), the luminescence decay times are strongly dependent on the Fe concentration, indicating that Fe centers act as predominant nonradiative recombination channels. Linear dependence of the decay time on the iron concentration allows estimation of the electron capture cross-section for the Fe3+ ions, which is equal to 1.9 x 10(-15) cm(2). The upper bound for the cross-section of the hole capture of Fe2+ was evaluated as 10 x 10(-15) cm

  • 4.
    Aggerstam, Thomas
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Electrumlaboratoriet, ELAB.
    Sjödin, Mikael
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Electrumlaboratoriet, ELAB.
    Lourdudoss, Sebastian
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Electrumlaboratoriet, ELAB.
    AlGaN/GaN high-electron-mobility transistors on sapphire with Fe-doped GaN buffer layer by MOVPE2006Ingår i: Physica Status Solidi C - Current Topics in Solid State Physics: Vol 3, No 6 / [ed] Hildebrandt S; Stutzmann M, 2006, Vol. 3, s. 2373-2376Konferensbidrag (Refereegranskat)
    Abstract [en]

    A simple AlGaN/GaN HEMT structure without any interlayer on Fe-doped GaN (GaN:Fe) grown by LP-MOVPE in one single run on sapphire is demonstrated. The surface segregation of Fe in GaN occurring during growth is identified. Hall measurements yield 2DEG (two dimensional electron gas) mobilities of 1700 and 10700 cm2/Vs and sheet carrier concentrations of 5.1×10 12 and 5.7×1012 cm-2 at 300 K and 20 K, respectively. Good pinch-off current-voltage (ID-VD) characteristics is observed from AlGaN/GaN HEMTs. A maximum drain current density of 0.6 A/mm and a peak extrinsic transconductance of 200 mS/mm have been observed. The HEMT structure yields very good device isolation as indicated by an isolation current of ≀1 nA at 20 V.

  • 5.
    Akram, Nadeem
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik, Fotonik.
    Kjebon, Olle
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik, Fotonik.
    Chacinski, Marek
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP. KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik, Fotonik.
    Schatz, Richard
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP. KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik, Fotonik.
    Berggren, Jesper
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Materialfysik, Halvledarmaterial, HMA.
    Olsson, Fredrik
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Materialfysik, Halvledarmaterial, HMA.
    Lourdudoss, Sebastian
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Materialfysik, Halvledarmaterial, HMA.
    Berrier, Audrey
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Experimental characterization of high-speed 1.55 mu m buried heterostructure InGaAsP/InGaAlAs quantum-well lasers2009Ingår i: Journal of the Optical Society of America. B, Optical physics, ISSN 0740-3224, E-ISSN 1520-8540, Vol. 26, nr 2, s. 318-327Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Detailed experimental characterization is performed for 1550 nm semi-insulating regrown buried heterostructure Fabry-Perot (FP) lasers having 20 InGaAsP/InGaAlAs strain-balanced quantum wells (QWs) in the active region. Light-current-voltage performance, electrical impedance, small-signal response below and above threshold, amplified spontaneous emission spectrum below threshold and relative intensity noise spectrum are measured. Different laser parameters such as external differential quantum efficiency eta(d), background optical loss alpha(i), K-factor, D-factor, characteristic temperature T-0, differential gain dg/dn, gain-compression factor epsilon, carrier density versus current, differential carrier lifetime tau(d), optical gain spectrum below threshold, and chirp parameter alpha are extracted from these measurements. The FP lasers exhibited a high T-0 (78-86.5 degrees C) and very high-resonance frequency (23.7 GHz). The results indicate that appropriately designed lasers having a large number of InGaAsP well/InGaAlAs barrier QWs with shallow valence-band discontinuity can be useful for un-cooled high-speed direct-modulated laser applications.

  • 6.
    Akram, Nadeem
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik, Fotonik.
    Kjebon, Olle
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik, Fotonik.
    Chacinski, Marek
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik, Fotonik.
    Schatz, Richard
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik, Fotonik.
    Berggren, Jesper
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Olsson, Fredrik
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Lourdudoss, Sebastian
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Berrier, Audrey
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    High-Speed Performance of 1.55 µm Buried Hetero-Structure Lasers with 20 InGaAsP/InGaAlAs Quantum-Wells2006Ingår i: 2006 European Conference on Optical Communications Proceedings, ECOC 2006, IEEE , 2006, s. 1-2Konferensbidrag (Refereegranskat)
    Abstract [en]

    1550 nm re-grown FP lasers having 20 InGaAsP/InGaAlAs strain-balanced QWs exhibit low threshold current density, high T0 (78.0 #x000B0;C) and high resonance frequency (24 GHz) indicating that a large number of shallow barrier QWs are attractive for un-cooled high-speed direct-modulation applications.

  • 7.
    Akram, Nadeem
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Kjebon, Olle
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Marcinkevičius, Saulius
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Schatz, Richard
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Berggren, Jesper
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Olsson, Fredrik
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Lourdudoss, Sebastian
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    The effect of barrier composition on the vertical carrier transport and lasing properties of 1.55-mu m multiple quantum-well structures2006Ingår i: IEEE Journal of Quantum Electronics, ISSN 0018-9197, E-ISSN 1558-1713, Vol. 42, nr 7, s. 713-714Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this paper, the effect of barrier bandgap and composition on the optical performance of 1.55-mu m InGaAsP/In-GaAsP and InGaAsP/InGaAlAs multiple quantum-well structures and Fabry-Perot lasers is evaluated experimentally. Direct vertical carrier transport measurements were performed through strain-compensated multiple quantum-well (MQW) test structures using femto-second laser pulse excitation and time-resolved photoluminescence up-conversion method. MQW test structures were grown with different barrier composition (InGaAsP and InGaAlAs) and barrier bandgap (varied from lambda(g) = 1440 to 1260 nm) having different conduction band Delta E-c and valence band discontinuity Delta E-v, while keeping the same InGaAsP well composition for all the structures. The ambipolar carrier transport was found to be faster in the structures with lower valence band discontinuity Delta E-v. Regrown semi-insulating buried heterostructure Fabry-Perot (SIBH-FP) lasers were fabricated from similar QWs and their static light-current-voltage characteristics (including optical gain and chirp spectra below threshold) and thermal characteristics were measured. Lasers with InGaAlAs barrier showed improved high-temperature operation, higher optical gain, higher differential gain, and lower chirp, making them suitable candidates for high-bandwidth directly modulated uncooled laser applications.

  • 8. Andersson, T. G.
    et al.
    Liu, X. Y.
    Aggerstam, Thomas
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Holmström, Petter
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Lourdudoss, Sebastian
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Thylen, Lars
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Chen, Y. L.
    Hsieh, C. H.
    Lo, I.
    Macroscopic defects in GaN/AlN multiple quantum well structures grown by MBE on GaN templates2009Ingår i: Microelectronics Journal, ISSN 0026-2692, Vol. 40, nr 2, s. 360-362Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We have used MBE to grow in AlN/GaN superlattices, with different number of periods, on 2.5-mu m-thick MOVPE-GaN templates to study the development of defects such as surface deformation due to strain. After growth the samples were studied by atomic force microscopy (AFM), transmission electron microscopy (TEM), XRD and Fourier transform infrared spectroscopy (FT-IR). The strain increased with the number of quantum wells (QWs) and eventually caused defects such as microcracks visible by optical microscopy at four or more QW periods. High-resolution TEM images showed shallow recessions on the surface (surface deformation) indicating formation of microcracks in the MQW region. The measured intersubband (IS) absorption linewidth from a four period structure was 97 meV, which is comparable with the spectrum from a 10 period structure at an absorption energy of similar to 700 meV. This indicates that the interface quality of the MQW is not substantially affected by the presence of cracks.

  • 9.
    Angulo Barrios, C.
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Lourdudoss, Sebastian
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT. KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Messmer, L. R.
    Holmgren, M.
    Lovqvist, A.
    Carlsson, C.
    Larsson, A.
    Halonen, J.
    Ghisoni, M.
    Stevens, Renaud
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Schatz, Richard
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP. KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    GaAs/AlGaAs buried-heterostructure laser diodes with semi-insulating GaInP:Fe regrowth2001Ingår i: Lasers and Electro-Optics, 2001. CLEO/Pacific Rim 2001. The 4th Pacific Rim Conference on, 2001, Vol. 2Konferensbidrag (Refereegranskat)
    Abstract [en]

    GaAs/AlGaAs buried-heterostructure in-plane lasers and vertical-cavity surface-emitting lasers using GaInP:Fe as the burying layer have been fabricated and investigated. Regrowth of GaInP:Fe around etched laser mesas was achieved by hydride vapor phase epitaxy. The lasers exhibit good performance under CW operation and show promising high-speed characteristics.

  • 10. Arulkumaran, S.
    et al.
    Ng, G. I.
    Tan, C. L.
    Liu, Z. H.
    Bu, J.
    Radhakrishnan, K.
    Aggerstam, T.
    Sjodin, M.
    Lourdudoss, Sebastian
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Enhancement of both direct-current and microwave characteristics of AlGaN/GaN high-electron-mobility transistors by furnace annealing2006Ingår i: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 88, nr 2Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The enhancement of both direct-current (dc) and microwave characteristics of AlGaN/GaN high-electron-mobility transistors (HEMTs) were demonstrated by conventional furnace annealing at 400 degrees C for 5 min. Due to the improvement in Ni/Au Schottky contact properties by furnace annealing, about 17%, 34%, 23%, and 25% of enhancements in maximum drain current density, maximum extrinsic transconductance (g(m max)), cutoff frequency and maximum oscillation frequency were observed, respectively. A positive threshold voltage shift and the increase in g(m max) can also be correlated to the improved Schottky parameters such as ideality factor and barrier height. The annealed devices exhibited low reverse gate-leakage-current by more than three orders of magnitude and low drain-leakage-current by two orders of magnitude. Correspondingly, the devices exhibited 55% of higher breakdown voltage after annealing. The furnace annealing is an effective and viable means to enhance both dc and microwave characteristics of AlGaN/GaN HEMTs.

  • 11. Azarov, A.Yu.
    et al.
    Hallén, Anders
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Jensen, J.
    Aggerstam, Thomas
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Lourdudoss, Sebastian
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    High dose Fe implantation of gan: Damage build-up and dopant redistribution2008Ingår i: PROCEEDINGS OF THE 17TH INTERNATIONAL VACUUM CONGRESS/13TH INTERNATIONAL CONFERENCE ON SURFACE SCIENCE/INTERNATIONAL CONFERENCE ON NANOSCIENCE AND TECHNOLOGY, 2008, Vol. 100, nr PART 4Konferensbidrag (Refereegranskat)
    Abstract [en]

    Undoped GaN epilayers implanted at room temperature with 50-325 keV Fe + ions in the fluence range of 1015 - 1017 ions/cm are studied by a combination of Rutherford backscattering/channeling spectrometry and time-of-flight elastic recoil detection analysis. Results show that for high ion fluences (>1 × 1016 cm-2) enhanced Fe concentration closer to the surface is observed. The Fe redistribution towards the surface increases as the ion fluence increases. Our findings are attributed to radiation enhanced diffusion during ion implantation and increasing of Fe diffusivity in the implantation-induced amorphous phase near the surface.

  • 12. Baek, J. H.
    et al.
    Soares, F. M.
    Seo, S. W.
    Jiang, W.
    Fontaine, N. K.
    Broeke, R. G.
    Cao, J.
    Olsson, Fredrik
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Materialfysik, Halvledarmaterial, HMA.
    Lourdudoss, Sebastian
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Materialfysik, Halvledarmaterial, HMA.
    Yoo, S. J. B.
    10-GHz and 20-GHz channel spacing high-resolution AWGs on InP2009Ingår i: IEEE Photonics Technology Letters, ISSN 1041-1135, E-ISSN 1941-0174, Vol. 21, nr 5, s. 298-300Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This letter reports on 10-GHz and 20-GHz channel-spacing arrayed waveguide gratings (AWGs) based on InP technology. The dimensions of the AWGs are 6.8 × 8.2 mm2 and 5.0 × 6.0 mm2, respectively, and the devices show crosstalk levels of 12 dB for the 10-GHz and 17 dB for the 20-GHz AWG without any compensation for the phase errors in the arrayed waveguides. The root-mean-square phase errors for the center arrayed waveguides were characterized by using an optical vector network analyzer, and are 18° for the 10-GHz AWG and 28° for the 10-GHz AWG.

  • 13. Barrios, C. A.
    et al.
    Lourdudoss, Sebastian
    KTH, Tidigare Institutioner (före 2005), Mikroelektronik och informationsteknik, IMIT.
    Martinsson, H.
    Analysis of leakage current in GaAs/AlGaAs buried-heterostructure lasers with a semi-insulating GaInP: Fe burying layer2002Ingår i: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 92, nr 5, s. 2506-2517Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The leakage current in recently demonstrated GaAs/AlGaAs buried heterostructure (BH) lasers with a semi-insulating (SI) GaInP:Fe burying layer has been theoretically and experimentally analyzed. Calculated current-voltage characteristics of n-GaAs/SI-GaInP/n-GaAs and p-GaAs/SI-GaInP/p-GaAs planar configurations have been studied specially to assess the behavior of SI-GaInP:Fe under electron and hole injection. Two-dimensional potential profiles have been used to explain the leakage current mechanism in the SI-GaInP-buried lasers. Simulations reveal that the total leakage current decreases as the active trap concentration in the SI-GaInP:Fe burying layer is increased as expected, but the leakage current is strongly confined in the vicinity of the active region where the local leakage current density increases significantly as the trap density increases. It is found that the insertion of a n-GaInP hole blocking layer between the p-metal and the SI-GaInP layer decreases the total leakage current. Experimental light-current and current-voltage characteristics of fabricated lasers with and without an additional n-GaInP layer, and electroluminescence (EL) emitted from the burying GaInP:Fe layers corroborate qualitatively the simulations and demonstrate the benefits of using a n-GaInP layer for reducing leakage current in these type of lasers.

  • 14. Barrios, C. A.
    et al.
    Messmer, E. R.
    Holmgren, M.
    Lourdudoss, Sebastian
    KTH, Tidigare Institutioner (före 2005), Mikroelektronik och informationsteknik, IMIT.
    GaAs/AlGaAs buried heterostructure laser by wet etching and semi-insulating GaInP: Fe regrowth2000Ingår i: Electrochemical and solid-state letters, ISSN 1099-0062, E-ISSN 1944-8775, Vol. 3, nr 9, s. 439-441Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Selective regrowth of semi-insulating Ga0.51In0.49P:Fe (SI-GaInP:Fe) by hydride vapor-phase epitaxy around Al-containing wet etched laser mesas is used for the first time to fabricate a GaAs/AlGaAs buried heterostructure laser emitting at 808 nm. The reverse and forward current-voltage characteristics measured at different temperatures up to 80 degrees C indicate no serious leakage current problems. The performance of the laser shows that the SI-GaInP: Fe burying layer fulfills its function as a current and optical confinement layer. The fabrication procedure and the laser characteristics are presented.

  • 15. Barrios, C. A.
    et al.
    Messmer, E. R.
    Holmgren, M.
    Risberg, A.
    Halonen, J.
    Lourdudoss, Sebastian
    KTH, Tidigare Institutioner (före 2005), Mikroelektronik och informationsteknik, IMIT.
    Epitaxially regrown GaAs/AlGaAs laser mesas with semi-insulating GaInP: Fe and GaAs : Fe2001Ingår i: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 30, nr 8, s. 987-991Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Selective regrowth of semi-insulating iron-doped Ga0.51In0.49P (SI-GaInP:Fe) and SI-GaAs:Fe around GaAs/AlGaAs mesas by hydride vapor phase epitaxy (HVPE) has been achieved. A HCl based in-situ cleaning procedure has been used to remove aluminum oxide from the etched walls of the mesas. Regrowth conducted without proper cleaning results in an irregular interface with voids. Regrowth morphology aspects are also presented. Our cleaning and regrowth methods have been used for fabricating GaAs/AlGaAs buried heterostructure in-plane lasers and vertical-cavity surface-emitting lasers.

  • 16. Barrios, C. A.
    et al.
    Messmer, E. R.
    Risberg, A.
    Carlsson, C.
    Halonen, J.
    Ghisoni, M.
    Larsson, A.
    Lourdudoss, Sebastian
    KTH, Tidigare Institutioner (före 2005), Mikroelektronik och informationsteknik, IMIT.
    GaAs/AlGaAs buried-heterostructure vertical-cavity surface-emitting laser with semi-insulating GalnP: Fe regrowth2000Ingår i: Electronics Letters, ISSN 0013-5194, E-ISSN 1350-911X, Vol. 36, nr 18, s. 1542-1544Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The authors report the first results of a GaAs/AlGaAs buried-heterostructure vertical-cavity surface-emitting laser (VCSEL) with semi-insulating Ga0.51In0.49P:Fe (SI-GaInP:Fe) as the burying layer. Regrowth of SI-GaInP:Fe around 15 mu m diameter and 8 mu m tall VCSEL mesas was carried out by hydride vapour phase epitaxy (HVPE). Under room temperature continuous wave (CW) operation. the device exhibited a threshold current of 3.5mA, a differential quantum efficency of 33% and a light output power of 4.2mW. CW operation at temperatures up to 97 degrees C is also demonstrated.

  • 17. Brocke, R. G.
    et al.
    Cao, J.
    Fontaine, N. K.
    Ji, C.
    Chubun, N.
    Olsson, Fredrik
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Lourdudoss, Sebastian
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Kolner, B. H.
    Heritage, J. P.
    Yoo, S. J. B.
    Phase characterization of an InP based Optical-CDMA encoder using Frequency-Resolved Optical Gating (FROG)2005Ingår i: 2005 IEEE LEOS Annual Meeting Conference Proceedings (LEOS), 2005, s. 123-124Konferensbidrag (Refereegranskat)
    Abstract [en]

    We demonstrate the optical phase characterization of a monolithically integrated InP optical-CDMA encoder/decoder chip using frequency-resolved optical gating.

  • 18. Broeke, Ronald G.
    et al.
    Cao, Jin
    Ji, Chen
    Seo, Sang-Woo
    Du, Yixue
    Fontaine, Nick K.
    Baek, Jong-Hwa
    Yan, John
    Soares, Francisco M.
    Olsson, Fredrik
    Lourdudoss, Sebastian
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Pham, Anh-Vu H.
    Sheam, Michael
    Scherer, Axel
    Yoo, S. J. Ben
    Optical-CDMA in InP2007Ingår i: IEEE Journal of Selected Topics in Quantum Electronics, ISSN 1077-260X, E-ISSN 1558-4542, Vol. 13, nr 5, s. 1497-1507Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper describes the InP platforms for photonic integration and the development on these platforms of an optical code division multiple access (O-CDMA) system for local area networks. We demonstrate three building blocks of this system: an optical pulse source, an encoder/decoder pair, and a threshold detector. The optical pulse source consists of an integrated colliding pulse-mode laser with nearly transform-limited 10 Gb/s pulses and optical injection locking to an external clock for synchronization. The encoder/decoder pair is based on arrayed waveguide gratings. Bit-error-rate measurements involving six users at 10 Gb/s showed error-free transmission, while O-CDMA codes were calibrated using frequency resolved optical gating. For threshold detection after the decoder, we compared two Mach-Zehnder interferometer (MZI)-based optical thresholding schemes and present results on a new type of electroabsorber-based MZI.

  • 19. Cao, J.
    et al.
    Broeke, R. G.
    Fontaine, N.
    Cong, W.
    Ji, C.
    Du, Y.
    Chubun, N.
    Aihara, K.
    Pham, A. -V
    Heritage, J. P.
    Kolner, B. H.
    Yoo, S. J. B.
    Olsson, F.
    Lourdudoss, Sebastian
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik.
    Stephan, P. L.
    Error-free spectral encoding and decoding operation of InP O-CDMA encoder2006Ingår i: 2006 Optical Fiber Communication Conference, and the 2006 National Fiber Optic Engineers Conference, 2006Konferensbidrag (Refereegranskat)
    Abstract [en]

    We report error-free spectral encoding and decoding operation of an InP monolithic, ultra-compact optical-CDMA encoder/decoder photonic chip pair. The experimental results demonstrate the strong potential for realizing high performance O-CDMA networks with InP micro-systems.

  • 20.
    Cao, J.
    et al.
    Univ Calif Davis, Dept Elect & Comp Engn, Davis, CA 95616 USA..
    Broeke, R. G.
    Univ Calif Davis, Dept Elect & Comp Engn, Davis, CA 95616 USA..
    Fontaine, N.
    Univ Calif Davis, Dept Elect & Comp Engn, Davis, CA 95616 USA..
    Cong, W.
    Univ Calif Davis, Dept Elect & Comp Engn, Davis, CA 95616 USA..
    Ji, C.
    Univ Calif Davis, Dept Elect & Comp Engn, Davis, CA 95616 USA..
    Du, Y.
    Univ Calif Davis, Dept Elect & Comp Engn, Davis, CA 95616 USA..
    Chubun, N.
    Univ Calif Davis, Dept Elect & Comp Engn, Davis, CA 95616 USA..
    Aihara, K.
    Univ Calif Davis, Dept Elect & Comp Engn, Davis, CA 95616 USA..
    Pharn, Anh-Vu
    Univ Calif Davis, Dept Elect & Comp Engn, Davis, CA 95616 USA..
    Heritage, J. P.
    Univ Calif Davis, Dept Elect & Comp Engn, Davis, CA 95616 USA..
    Kolner, B. H.
    Univ Calif Davis, Dept Elect & Comp Engn, Davis, CA 95616 USA..
    Yoo, S. J. B.
    Univ Calif Davis, Dept Elect & Comp Engn, Davis, CA 95616 USA..
    Olsson, F.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Lourdudoss, Sebastian
    KTH, Tidigare Institutioner (före 2005), Mikroelektronik och informationsteknik, IMIT.
    Stephan, P. L.
    Lawrence Livermore Natl Lab, Livermore, CA 94550 USA..
    Error-free spectral encoding and decoding operation of InPO-CDMA encoder2006Ingår i: 2006 OPTICAL FIBER COMMUNICATION CONFERENCE/NATIONAL FIBER OPTIC ENGINEERS CONFERENCE, VOLS 1-6, OPTICAL SOC AMERICA , 2006, s. 843-+Konferensbidrag (Refereegranskat)
    Abstract [en]

    We report error-free spectral encoding and decoding operation of an InP monolithic, ultra-compact optical-CDMA encoder/decoder photonic chip pair. The experimental results demonstrate the strong potential for realizing high performance O-CDMA networks with InP micro-systems. (C) 2006 Optical Society of America.

  • 21. Cao, J.
    et al.
    Broeke, R. G.
    Ji, C.
    Du, Y.
    Chubun, N.
    Bjeletich, P.
    Tekin, T.
    Stephan, P. L.
    Olsson, F
    Lourdudoss, Sebastian
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik, Halvledarmaterial, HMA.
    Yoo, S. J. B.
    Spectral encoding and decoding of monolithic InP OCDMA encoder2005Ingår i: 31st European Conference on Optical Communications (ECOC 2005), 2005, Institution of Engineering and Technology, 2005, Vol. 2005, nr CP502, s. 501-502Konferensbidrag (Refereegranskat)
    Abstract [en]

    We report the optical-coding operation of monolithic, ultra-compact optical-CDMA encoder and decoder pair, consisting of InP based integrated AWGs and phase modulators. The encoder and decoder successfully demonstrate eight-bit Walsh code based encoding and decoding.

  • 22. Cao, J.
    et al.
    Broeke, R. G.
    Ji, C.
    Du, Y.
    Chubun, N.
    Bjeletich, P.
    Yoo, S. J. B.
    Olsson, Fredrik
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Lourdudoss, Sebastian
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Stephan, P. L.
    A monolithic ultra-compact inp o-cdma encoder with: Planarization by hvpe regrowth2006Ingår i: OFC/NFOEC, Optical Society of America, 2006Konferensbidrag (Refereegranskat)
    Abstract [en]

    We report a monolithic, ultra-compact optical-CDMA encoder/decoder photonic chip in InP with surface planarization by low-pressure Hydride-Vapor-Phase-Epitaxy regrowth. The chip consists of an AWG pair and eight electro-optic phase shifters and demonstrated excellent encoding operation.

  • 23. Cao, J.
    et al.
    Broeke, R. G.
    Ji, C.
    Du, Y.
    Chubun, N.
    Bjeletich, P.
    Yoo, S. J. B.
    Olsson, Fredrik
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Lourdudoss, Sebastian
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Stephan, P. L.
    A monolithic ultra-compact inp o-cdma encoder with: Planarization by hvpe regrowth2005Ingår i: Optics InfoBase Conference Papers, Optics Info Base, Optical Society of America, 2005Konferensbidrag (Refereegranskat)
    Abstract [en]

    We report a monolithic, ultra-compact optical-CDMA encoder/decoder photonic chip in InP with surface planarization by low-pressure Hydride-Vapor-Phase-Epitaxy regrowth. The chip consists of an AWG pair and eight electro-optic phase shifters and demonstrated excellent encoding operation.

  • 24.
    Cao, Jing
    et al.
    Department of Electrical and Computer Engineering, University of California.
    Broeke, R. G.
    Department of Electrical and Computer Engineering, University of California.
    Fontaine, N. K.
    Department of Electrical and Computer Engineering, University of California.
    Ji, C.
    Department of Electrical and Computer Engineering, University of California.
    Du, Y.
    Department of Electrical and Computer Engineering, University of California.
    Chubun, N.
    Department of Electrical and Computer Engineering, University of California.
    Aihara, K.
    Department of Electrical and Computer Engineering, University of California.
    Pham, Anh-Wu
    Department of Electrical and Computer Engineering, University of California.
    Olsson, Fredrik
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Lourdudoss, Sebastian
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Yoo, S. J. Ben
    Department of Electrical and Computer Engineering, University of California.
    Demonstration of Spectral Phase O-CDMA Encoding and Decoding in Monolithically Integrated Arrayed-Waveguide-Grating-Based Encoder2006Ingår i: IEEE Photonics Technology Letters, ISSN 1041-1135, E-ISSN 1941-0174, Vol. 18, nr 21-24, s. 2602-2604Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We report on successful spectral phase encoding and decoding operation in a pair of monolithically integrated InP encoder chips, each consisting of an arrayed waveguide grating (AWG) pair and an eight-channel electrooptic phase shifter array. The monolithic fabrication process includes anisotropic reactive ion etching and planarizing hydride-vapor-phase-epitaxy lateral regrowth to realize buried hetero-waveguide structures in AWGs and phase shifters. Electrooptical modulation in the phase shifter arrays in the encoder chip achieved Walsh-code-based optical code-division multiple access (O-CDMA) encoding and decoding. The matched-code encoding-decoding operation resulted in error-free performance in the presence of an interferer, indicating good potential for O-CDMA network applications.

  • 25. Carlsson, C.
    et al.
    Barrios, C. A.
    Messmer, E. R.
    Lovqvist, A.
    Halonen, J.
    Vukusic, J.
    Ghisoni, M.
    Lourdudoss, Sebastian
    KTH, Tidigare Institutioner (före 2005), Mikroelektronik och informationsteknik, IMIT.
    Larsson, A.
    Performance characteristics of buried heterostructure VCSELs using semi-insulating GaInP: Fe regrowth2001Ingår i: IEEE Journal of Quantum Electronics, ISSN 0018-9197, E-ISSN 1558-1713, Vol. 37, nr 7, s. 945-950Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We have fabricated GaAs-AlGaAs buried heterostructure vertical cavity surface emitting lasers, emitting at 850 nm, using semi-insulating GaInP:Fe regrowth and investigated their static properties. Lasers of different size (10-21 mum) have threshold currents in the range 2.8-7.0 mA, and produce a maximum output power of 1.7-6.0 mW at room temperature. The variation of threshold current with device size shows that the leakage current at the regrowth interface accounts for a significant part of the injection current. In spite of this, a differential quantum efficiency in the range 20%-30% is obtained which indicates that the regrowth interface is smooth and does not introduce any significant scattering loss. Studies of the transverse mode properties suggest that the GaInP provides weak guiding, resulting in single mode operation up to an output power of 0.7 mW and a beam divergence of only 6 degrees for lasers as large as 10 mum.

  • 26.
    Cheung, S. T. S.
    et al.
    Univ Calif Davis, Dept Elect & Comp Engn, 1 Shields Ave, Davis, CA 95616 USA.
    Soares, F. M.
    Univ Calif Davis, Dept Elect & Comp Engn, 1 Shields Ave, Davis, CA 95616 USA.
    Baek, J. H.
    Univ Calif Davis, Dept Elect & Comp Engn, 1 Shields Ave, Davis, CA 95616 USA.
    Guan, B.
    Univ Calif Davis, Dept Elect & Comp Engn, 1 Shields Ave, Davis, CA 95616 USA.
    Olsson, Fredrik
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Materialfysik, Halvledarmaterial, HMA.
    Lourdudoss, Sebastian
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Materialfysik, Halvledarmaterial, HMA.
    Yoo, S. J. B.
    Univ Calif Davis, Dept Elect & Comp Engn, 1 Shields Ave, Davis, CA 95616 USA.
    Monolithically integrated 10-GHz ring colliding pulse mode-locked laser for on-chip coherent communications2012Ingår i: 2012 Conference on Lasers and Electro-Optics, CLEO 2012, 2012, s. 6326206-Konferensbidrag (Refereegranskat)
    Abstract [en]

    We report a 10-GHz ring resonator colliding pulse mode-locked (CPM) laser with tunable couplers for InP-based monolithically integrated optical coherent communication system applications. Optimization included adjusting the saturable absorber reverse bias, driving RF-frequency, and amplifier gain current. Hybrid mode-locking (HML) resulted in a minimal pulse width of 10.1ps for 6 nm spectral width.

  • 27. Darakchieva, V.
    et al.
    Monemar, B.
    Paskova, T.
    Einfeldt, S.
    Hommel, D.
    Lourdudoss, Sebastian
    KTH, Skolan för informations- och kommunikationsteknik (ICT).
    Phonons in strained AlGaN/GaN superlattices2007Ingår i: Physica Status Solidi. C, Current topics in solid state physics, ISSN 1610-1634, E-ISSN 1610-1642, Vol. 4, nr 1, s. 170-174Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Phonons in strained AlGaN/GaN superlattices (SLs) with constant periods but different Al composition have been studied using a combination of infrared spectroscopic ellipsometry and Raman scattering spectroscopy. The following SL modes were identified: i) AlGaN localized E1(TO) modes identified for the first time and AlGaN localized A1 (LO) phonons; ii) GaN localized E2, E1(TO) and A1(LO) phonons; iii) delocalized E1(LO) phonons; iv) A1(TO) phonon; v) two modes around 660 cm-1 and 594-625 cm-1, respectively, not predicted by theory. The effects of strain and composition on the phonon frequencies were established and discussed.

  • 28. Dhanabalan, D.
    et al.
    Ananthu, V.
    Akshita, K. V.
    Bhattacharya, S.
    Varadarajan, E.
    Ganesamoorthy, S.
    Moorthy Babu, S.
    Natarajan, V.
    Verma, S.
    Srivatsava, M.
    Lourdudoss, Sebastian
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Studies on Schottky Barrier Diodes Fabricated using Single-Crystal Wafers of β-Ga2O3 Grown by the Optical Floating Zone Technique2022Ingår i: Physica status solidi. B, Basic research, ISSN 0370-1972, E-ISSN 1521-3951, Vol. 259, nr 2, artikel-id 2100496Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    β-Ga2O3 is one of the most promising wide-bandgap materials for optoelectronic applications as well as a conducting substrate for GaN-based device technologies. Single crystals of undoped β-Ga2O3 are grown by the optical floating zone technique utilizing compressed dry air as growth atmosphere. The properties of β-Ga2O3 are highly anisotropic. Optimization of the processing recipe for wafers along different orientations suitable for device development is conducted. Structural, optical, and electrical properties of the wafers are determined. Efforts are made to fabricate Schottky diodes based on Pt/Ti/Au–β-Ga2O3–Ti/Au device structures. Devices are fabricated on (−201) cut wafers. The device characteristics are discussed in detail.

  • 29. Douheret, O.
    et al.
    Anand, Srinivasan
    KTH, Tidigare Institutioner (före 2005), Mikroelektronik och informationsteknik, IMIT.
    Barrios, C. A.
    Lourdudoss, Sebastian
    KTH, Tidigare Institutioner (före 2005), Mikroelektronik och informationsteknik, IMIT.
    Characterization of GaAs/AlGaAs laser mesas regrown with semi-insulating GaInP by scanning capacitance microscopy2002Ingår i: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 81, nr 6, s. 960-962Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this work, cross-sectional scanning capacitance microscopy (SCM) is used to investigate GaAs/AlGaAs buried heterostructure lasers. Laser mesas are buried with GaInP:Fe selectively regrown by hydride vapor phase epitaxy. It is shown that a complete 2D map of the electrical properties of device structure including, delineation of regrown interfaces and electrical nature of the regrown GaInP layer can be obtained. The behavior of the SCM signal with ac bias is used to verify the semi-insulating nature of the regrown layer at different locations of the sample. The measured SCM signal for the regrown GaInP:Fe layer is uniformly zero, indicating very low free carrier densities and confirming semi-insulating properties. This observation strongly suggests, in addition, uniform Fe incorporation in the regrown layers, close to and far away from the mesa. Finally, a nanoscale feature in the SCM contrast appearing as a bright (dark) spot in dC/dV mode (feedback bias mode) is observed at the mesa sidewall close to the interface between the regrown GaInP:Fe and the p-cladding layer. The origin of this contrast is discussed in terms of local band-bending effects and supported by 2D Poisson simulations of the device structure.

  • 30. Estephan, Elias
    et al.
    Saab, Marie-belle
    Larroque, Christian
    Martin, Marta
    Olsson, Fredrik
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Lourdudoss, Sebastian
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Gergely, Csilla
    Peptides for functionalization of InP semiconductors2009Ingår i: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 337, nr 2, s. 358-363Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The challenge is to achieve high specificity in molecular sensing by proper functionalization of micro/nano-structured semiconductors by peptides that reveal specific recognition for these structures. Here we report on surface modification of the InP semiconductors by adhesion peptides produced by the phage display technique. An M13 bacteriophage library has been used to screen 10(10) different peptides against the InP(0 0 1) and the InP(1 1 1) surfaces to finally isolate specific peptides for each orientation of the InP. MALDI-TOF/TOF mass spectrometry has been employed to study real affinity of the peptide towards the InP surfaces. The peptides serve for controlled placement of biotin onto InP to bind then streptavidin. Our Atomic Force Microscopy study revealed a total surface coverage of molecules when the InP surface was functionalized by its specific biotinylated peptide (YAIKGPSHFRPS). Finally, fluorescence microscopy has been employed to demonstrate the preferential attachment of the peptide onto a micro-patterned InP surface. Use of substrate specific peptides could present an alternative solution for the problems encountered in the actually existing sensing methods and molecular self-assembly due to the unwanted unspecific interactions.

  • 31. Fontaine, N. K.
    et al.
    Baek, J. -H
    Ji, C.
    Broeke, R. G.
    Zhou, X.
    Seo, S. -W
    Soares, F. M.
    Shearn, M.
    Scherer, A.
    Olsson, Fredrik E.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Lourdudoss, Sebastian
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Liu, K. Y.
    Tsang, W. T.
    Yoo, S. J. B.
    Monolithically integratable colliding pulse modelocked laser source for O-CDMA photonic chip development2008Konferensbidrag (Refereegranskat)
    Abstract [en]

    We demonstrate modelocking of a colliding-pulse mode-locked laser formed by 3-μm-deep etched-mirrors on an InP platform for integration with passive waveguide components. Timing jitter of 243 fs and pulse width of 10 ps were measured.

  • 32. Fontaine, N. K.
    et al.
    Wei, J.
    Soares, F. M.
    Broeke, R. G.
    Seo, S. -W
    Baek, J. -H
    Cao, J.
    Okamoto, K.
    Yoo, S. J. B.
    Olsson, Fredrik
    Lourdudoss, Sebastian
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Determination of 20 GHz InP AWG phase errors by measurement of AWG pulse train2007Ingår i: 2007 IEEE LEOS Annual Meeting Conference Proceedings, IEEE , 2007, s. 725-726Konferensbidrag (Refereegranskat)
    Abstract [en]

    The phase errors of a 20 GHz AWG fabricated on InP are determined by measuring the intensity and phase of the pulse train produced by the transmission of a short pulse through an AWG.

  • 33. Gaarder, A.
    et al.
    Marcinkevicius, Saulius
    KTH, Tidigare Institutioner (före 2005), Mikroelektronik och informationsteknik, IMIT.
    Barrios, C. A.
    Lourdudoss, Sebastian
    KTH, Tidigare Institutioner (före 2005), Mikroelektronik och informationsteknik, IMIT.
    Time-resolved micro-photoluminescence studies of deep level distribution in selectively regrown GaInP: Fe and GaAs : Fe2002Ingår i: Semiconductor Science and Technology, ISSN 0268-1242, E-ISSN 1361-6641, Vol. 17, nr 2, s. 129-134Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We apply time-resolved photoluminescence with 1-2 mum spatial resolution for the characterization of deep centre distributions in semi-insulating GaInP:Fe and GaAs:Fe epitaxial layers regrown by hydride vapour phase epitaxy around etched GaAs mesas and GaAs/AlGaAs quantum well laser structures. In InGaP, Fe ions act as the main carrier recombination centres, while in Fe-doped GaAs both the Fe ions and As antisite defects have to be considered. The distribution of Fe ions in InGaP was found to be rather uniform and close to the target value. For GaAs:Fe, the number of ionized Fe and EL2 centres showed a certain increase at the mesa interfaces. In both cases, the high trap concentration was maintained throughout the regrown layers indicating good semi-insulating material properties.

  • 34. Gaarder, A.
    et al.
    Marcinkevicius, Saulius
    KTH, Tidigare Institutioner (före 2005), Mikroelektronik och informationsteknik, IMIT.
    Barrios, C. A.
    Lourdudoss, Sebastian
    KTH, Tidigare Institutioner (före 2005), Mikroelektronik och informationsteknik, IMIT.
    Time-resolved micro-photoluminescence studies of dopant distribution in selectively regrown GalnP: Fe around VCSELs2002Ingår i: Physica Scripta, ISSN 0031-8949, E-ISSN 1402-4896, Vol. T101, s. 89-91Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We apply time-resolved photoluminescence with 1.5 mum spatial resolution for characterization ofcarrier trap distribution in semi-insulating Ga0.51In0.49P:Fe layers regrown around GaAs/AlGaAs circular vertical cavity surface emitting laser mesas using hydride vapour phase epitaxy. The carrier trapping times are in the range from 10 to 15 ps and quite uniformly distributed throughout the burying GaInP:Fe layer, suggesting that the layer is semi-insulating everywhere. Simulations show that, in addition to the Fe dopants, the layer contains other, unintended carrier traps. The photoluminescence spectra reveal that the regrown GaInP:Fe material has several distinct regions with different band gaps. This is attributed to differences in the In/Ga composition and/or CuPt ordering of the GaInP.

  • 35. Gaarder, A.
    et al.
    Marcinkevicius, Saulius
    KTH, Tidigare Institutioner (före 2005), Mikroelektronik och informationsteknik, IMIT.
    Messmer, E. R.
    Lourdudoss, Sebastian
    KTH, Tidigare Institutioner (före 2005), Mikroelektronik och informationsteknik, IMIT.
    Dopant distribution in selectively regrown InP: Fe studied by time-resolved photoluminescence2001Ingår i: Journal of Crystal Growth, ISSN 0022-0248, E-ISSN 1873-5002, Vol. 226, nr 4, s. 451-457Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We apply time-resolved photoluminescence with 1 mum spatial resolution for the characterization of iron distribution in semi-insulating InP:Fe epitaxial layers regrown by hydride vapor-phase epitaxy around etched mesas. The InP:Fe regrowth was carried out on InP:S mesas etched both along the [110] and [110] crystallographic directions, as well as on InP/InGaAsP in-plane lasers. In all cases, the Fe concentration was found to be close to the target values and showed little variation along the regrown layers.

  • 36.
    Gu, Tian
    et al.
    MIT, Mat Res Lab, 77 Massachusetts Ave, Cambridge, MA 02139 USA.;MIT, Dept Mat Sci & Engn, 77 Massachusetts Ave, Cambridge, MA 02139 USA..
    Kim, Hyun Jung
    NASA, Langley Res Ctr, Hampton, VA 23681 USA..
    Lin, Hongtao
    Zhejiang Univ, Coll Informat Sci & Elect Engn, State Key Lab Modern Opt Instrumentat, Hangzhou 310027, Zhejiang, Peoples R China..
    Lourdudoss, Sebastian
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Zhou, Weidong
    Univ Texas Arlington, Dept Elect Engn, Arlington, TX 76019 USA..
    Hybrid Integrated Photonic Platforms: feature issue introduction2021Ingår i: Optical Materials Express, ISSN 2159-3930, E-ISSN 2159-3930, Vol. 11, nr 12, s. 4095-4096Artikel i tidskrift (Övrigt vetenskapligt)
    Abstract [en]

    Hybrid photonic integration and interfaces allow different optical materials and components to be combined on a single platform and thus are crucial to future integrated photonic systems. This feature issue covers frontier research, technologies, and perspectives in this rapidly-evolving area and aims to address the key challenges and requirements across a broad range of photonic technologies.

  • 37.
    Ha Ryu, Jae
    et al.
    Univ Wisconsin, Dept Elect & Comp Engn, 1415 Engn Dr, Madison, WI 53706 USA..
    Kirch, Jeremy D.
    Univ Wisconsin, Dept Elect & Comp Engn, 1415 Engn Dr, Madison, WI 53706 USA..
    Knipfer, Benjamin
    Univ Wisconsin, Dept Elect & Comp Engn, 1415 Engn Dr, Madison, WI 53706 USA..
    Liu, Zerui
    Univ Wisconsin, Dept Elect & Comp Engn, 1415 Engn Dr, Madison, WI 53706 USA..
    Turville-Heitz, Morgan
    Intraband LLC, 200 N Prospect Ave, Madison, WI 53726 USA..
    Earles, Tom
    Intraband LLC, 200 N Prospect Ave, Madison, WI 53726 USA..
    Marsland, Robert A.
    Intraband LLC, 200 N Prospect Ave, Madison, WI 53726 USA..
    Strömberg, Axel
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Omanakuttan, Giriprasanth
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Sun, Yan-Ting
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Lourdudoss, Sebastian
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Botez, Dan
    Univ Wisconsin, Dept Elect & Comp Engn, 1415 Engn Dr, Madison, WI 53706 USA..
    Mawst, Luke J.
    Univ Wisconsin, Dept Elect & Comp Engn, 1415 Engn Dr, Madison, WI 53706 USA..
    Beam stability of buried-heterostructure quantum cascade lasers employing HVPE regrowth2021Ingår i: Optics Express, E-ISSN 1094-4087, Vol. 29, nr 2, s. 2819-2826Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Measurements of beam stability for mid-infrared (IR)-emitting quantum cascade lasers (QCLs) are important for applications that require the beam to travel through air to remote targets, such as free-space communication links. We report beam-quality measurement results of narrow-ridge, 4.6 mu m-emitting buried-heterostructure (BH) QCLs fabricated using ICP etching and HVPE regrowth. Beam-quality measurements under QCW operation exhibit M-2 < 1.2 up to 1 W for similar to 5 mu m-wide ridges. 5 mu m-wide devices display some small degree of centroid motion with increasing output power (< 0.125 mrad), which corresponds to a targeting error of similar to 1.25 cm over a distance of 100 m.

  • 38.
    Hammar, Mattias
    et al.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Elektroteknik, Elektronik och inbyggda system, Integrerade komponenter och kretsar.
    Hallén, Anders
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Elektroteknik, Elektronik och inbyggda system, Elektronik och inbyggda system.
    Lourdudoss, Sebastian
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Compound Semiconductors2021Ingår i: Physica status solidi. B, Basic research, ISSN 0370-1972, E-ISSN 1521-3951, Vol. 258, nr 2Artikel i tidskrift (Refereegranskat)
  • 39.
    Hammar, Mattias
    et al.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Elektroteknik, Elektronik och inbyggda system, Integrerade komponenter och kretsar.
    Hallén, Anders
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Elektroteknik, Elektronik och inbyggda system, Integrerade komponenter och kretsar.
    Lourdudoss, Sebastian
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Compound Semiconductors2022Ingår i: Physica Status Solidi (a) applications and materials science, ISSN 1862-6300, E-ISSN 1862-6319, Vol. 219, nr 4, artikel-id 2200049Artikel i tidskrift (Övrigt vetenskapligt)
  • 40.
    Han, Mengyao
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik. Beijing Jiaotong Univ, Inst Lightwave Technol, Key Lab All Opt Network & Adv Telecommun Network, Minist Educ, Beijing 100044, Peoples R China..
    Joharifar, Mahdieh
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Wang, Muguang
    Beijing Jiaotong Univ, Inst Lightwave Technol, Key Lab All Opt Network & Adv Telecommun Network, Minist Educ, Beijing 100044, Peoples R China..
    Schatz, Richard
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Puerta, Rafael
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik. Ericsson AB, Ericsson Res, S-16483 Stockholm, Sweden..
    Sun, Yan-Ting
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Fan, Yuchuan
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik. RISE Res Inst Sweden, S-16440 Kista, Sweden..
    Maisons, Gregory
    mirSense, F-91120 Palaiseau, France..
    Abautret, Johan
    mirSense, F-91120 Palaiseau, France..
    Teissier, Roland
    mirSense, F-91120 Palaiseau, France..
    Zhang, Lu
    Zhejiang Univ, Coll Informat Sci & Elect Engn, Hangzhou 310027, Peoples R China.;Zhejiang Lab, Hangzhou 310027, Peoples R China..
    Spolitis, Sandis
    Riga Tech Univ, Inst Telecommun, LV-1048 Riga, Latvia..
    Bobrovs, Vjaceslavs
    Riga Tech Univ, Inst Telecommun, LV-1048 Riga, Latvia..
    Lourdudoss, Sebastian
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Yu, Xianbin
    Zhejiang Univ, Coll Informat Sci & Elect Engn, Hangzhou 310027, Peoples R China.;Zhejiang Lab, Hangzhou 310027, Peoples R China..
    Popov, Sergei
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Ozolins, Oskars
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik. RISE Res Inst Sweden, S-16440 Kista, Sweden.;Riga Tech Univ, Inst Telecommun, LV-1048 Riga, Latvia..
    Pang, Xiaodan
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik. RISE Res Inst Sweden, S-16440 Kista, Sweden.;Riga Tech Univ, Inst Telecommun, LV-1048 Riga, Latvia..
    High Spectral Efficiency Long-Wave Infrared Free-Space Optical Transmission With Multilevel Signals2023Ingår i: Journal of Lightwave Technology, ISSN 0733-8724, E-ISSN 1558-2213, Vol. 41, nr 20, s. 6514-6520Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study explores the potential of long-wave infrared free-space optical (FSO) transmission that leverages multilevel signals to attain high spectral efficiency. The FSO transmission system consists of a directly modulated-quantum cascade laser (DM-QCL) operating at 9.15 mu m and a mercury cadmium telluride (MCT) detector. To fully understand the system, we conduct measurements on the DM-QCL chip and MCT detector and assess the overall amplitude response of the DM-QCL, MCT detector, and all electrical components. We apply various signals, including on-off keying (OOK), 4-level pulse amplitude modulation (PAM4), 6-level PAM (PAM6), and 8-level PAM (PAM8) to maximize the bit rate and spectral efficiency of the FSO transmission. Through a two-dimensional sweeping of the laser bias current and MCT detector photovoltage, we optimize the transmission performance. At the optimal operation point, the FSO system achieved impressive results which are up to 6 Gbaud OOK, 3.5 Gbaud PAM4, 3 Gbaud PAM6, and 2.7 Gbaud PAM8 signal transmissions, with a bit error rate performance below 6.25% overhead hard decision-forward error correction limit when the DM-QCL operates at 10 degrees C. We also evaluate the eye diagrams and stability of the system to showcase its remarkable transmission performance. Our findings suggest that the DM-QCL and MCT detector-based FSO transceivers offer a highly competitive solution for the next generation of optical wireless communication systems.

  • 41.
    Holmström, Petter
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Liu, X. Y.
    Uchida, H.
    Aggerstam, Thomas
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Kikuchi, A.
    Kishino, K.
    Lourdudoss, Sebastian
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Andersson, T.G.
    Thylén, Lars
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Intersubband photonic devices by group-III nitrides2007Ingår i: Optoelectronic Materials And Devices II / [ed] Nakano, Y, 2007, Vol. 6782, s. N7821-N7821Konferensbidrag (Refereegranskat)
    Abstract [en]

    The characteristics of intersubband transitions in III-nitride quantum wells are promising for detectors and all-optical switches through a high intrinsic speed (similar to 1 THz), and can also provide a high optical saturation power and a desired small negative chirp parameter in electroabsorption modulators. The high LO-phonon energy allows to improve the operating temperature of THz emitters. Recent achievements and prospects for intersubband III-nitride photonic devices, mainly for lambda=1.55 mu m, are briefly reviewed. Further, means to enhance material quality by achieving crack-free growth of GaN/AlN multiple-quantum-well (MQW) structures, and by employing intersubband transitions in multiple-quantum-disk (MQD) structures incorporated into dislocation free GaN nanocolumns are discussed. We investigate the occurrence of cracks in MBE-grown GaN/AlN MQWs on GaN MOVPE templates with respect to the buffer layer, the number of QWs and the temperature reduction rate after growth. Intersubband absorption in GaN/AlN MQDs in the wavelength range 1.38-1.72 mu m is demonstrated in three samples grown on Si(111).

  • 42. Jahan, D.
    et al.
    Soderstrom, D.
    Lourdudoss, Sebastian
    KTH, Tidigare Institutioner (före 2005), Mikroelektronik och informationsteknik, IMIT.
    Kinetic study of InP: Fe growth by LP-HVPE with ferrocene as Fe source2000Ingår i: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 147, nr 2, s. 744-746Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A kinetic study of InP:Fe growth has been carried out in a low pressure hydride vapor phase epitaxy (LP-HVPE) reactor using Ferrocene as iron source. The influence of the ferrocene partial pressure on the growth behavior has been investigated. A drastic decrease of the growth rate in the presence of ferrocene has been experimentally measured. This effect is explained to be due to cyclopentadiene adsorption. A kinetic model, that takes into account this adsorption, is proposed, which explains the observed experimental results.

  • 43.
    Jaramillo-Fernandez, Juliana
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik.
    Chavez-Angel, Emigdio
    Sanatinia, Reza
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Laserfysik. Harvard Univ, USA.
    Kataria, Himanshu
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik. IRnova AB, Sweden.
    Anand, Srinivasan
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik.
    Lourdudoss, Sebastian
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik.
    Sotomayor-Torres, Clivia M.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik. CSIC, Spain; Barcelona Inst Sci & Technol, Spain; ICREA, Spain.
    Thermal conductivity of epitaxially grown InP: experiment and simulation2017Ingår i: CrystEngComm, ISSN 1466-8033, E-ISSN 1466-8033, Vol. 19, nr 14, s. 1879-1887Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The integration of III-V optoelectronic devices on silicon is confronted with the challenge of heat dissipation for reliable and stable operation. A thorough understanding and characterization of thermal transport is paramount for improved designs of, for example, viable III-V light sources on silicon. In this work, the thermal conductivity of heteroepitaxial laterally overgrown InP layers on silicon is experimentally investigated using microRaman thermometry. By examining InP mesa-like structures grown from trenches defined by a SiO2 mask, we found that the thermal conductivity decreases by about one third, compared to the bulk thermal conductivity of InP, with decreasing width from 400 to 250 nm. The high thermal conductivity of InP grown from 400 nm trenches was attributed to the lower defect density as the InP micro crystal becomes thicker. In this case, the thermal transport is dominated by phonon-phonon interactions as in a low defect-density monocrystalline bulk material, whereas for thinner InP layers grown from narrower trenches, the heat transfer is dominated by phonon scattering at the extended defects and InP/SiO2 interface. In addition to the nominally undoped sample, sulfur-doped (1 x 10(18) cm(-3)) InP grown on Si was also studied. For the narrower doped InP microcrystals, the thermal conductivity decreased by a factor of two compared to the bulk value. Sources of errors in the thermal conductivity measurements are discussed. The experimental temperature rise was successfully simulated by the heat diffusion equation using the FEM.

  • 44.
    Jaskorzynska, Bozena
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Kista Photonics Research Center, KPRC.
    Wosinski, Lech
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Kista Photonics Research Center, KPRC.
    Lourdudoss, Sebastian
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Kista Photonics Research Center, KPRC.
    Olsson, Fredrik
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP. KTH, Skolan för informations- och kommunikationsteknik (ICT), Centra, Kista Photonics Research Center, KPRC.
    Active Si-based photonics via heterogeneous integration2008Ingår i: ICTON 2008: PROCEEDINGS OF 2008 10TH ANNIVERSARY INTERNATIONAL CONFERENCE ON TRANSPARENT OPTICAL NETWORKS, VOL 2 / [ed] Marciniak, M, NEW YORK: IEEE , 2008, s. 30-33Konferensbidrag (Refereegranskat)
    Abstract [en]

    We review major breakthroughs in realizing silicon-based active components by heterogeneous integration with III-V semiconductors, or nonlinear organic materials. In more detail we describe examples of our concepts and technological approach addressing this goal. This includes designs for widely tunable filters and new routes for heteroepitaxy and selective area growth of InP on silicon.

  • 45. Ji, C.
    et al.
    Broeke, R. G.
    Du, Y.
    Cao, J.
    Chubun, N.
    Bjeletich, P.
    Olsson, F.
    Lourdudoss, Sebastian
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Welty, R.
    Reinhardt, C.
    Stephan, P. L.
    Yoo, S. J. B.
    Monolithically integrated InP-based photonic chip development for O-CDMA systems2005Ingår i: IEEE Journal of Selected Topics in Quantum Electronics, ISSN 1077-260X, E-ISSN 1558-4542, Vol. 11, nr 1, s. 66-77Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper discusses photonic integration efforts toward developing an InP-based inonolithically integrated photonic chip for optical code-division multiple-access (O-CDMA) system applications. The chip design includes the colliding pulsed mode (CPM) locked laser, the. Mach-Zehnder interferometer-based threshold detector (MZI), and the monolithic O-CDMA encoder/decoder chip based on array-waveguide-gratings and phase modulator arrays. The compact 4 x I cm monolithic chip can replace a complex and large O-CDMA setup based on bulk optics. The integration technique involves active-passive integration using dry etching, metal organic chemical vapor deposition growth, and lateral hydride vapor phase epitaxy regrowth technologies. The fabricated CPM showed stable 1.54 ps modelocked laser output, the MZI showed excellent O-CDMA threshold detection, and the O-CDMA encoder showed Walsh-code O-CDMA, encoding. Further, the fabricated devices showed excellent planarity, which accelerate our progress toward monolithic integration of O-CDMA systems.

  • 46. Jiang, W.
    et al.
    Fontaine, K.
    Soares, F. M.
    Baek, J. H.
    Okamoto, K.
    Yoo, J. B.
    Olsson, Fredrik
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik, Halvledarmaterial, HMA.
    Lourdudoss, Sebastian
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik, Halvledarmaterial, HMA.
    Dynamic phase-error compensation for high-resolution InP arrayed-waveguide grating using electro-optic effect2008Ingår i: Conference Proceedings - Lasers and Electro-Optics Society Annual Meeting-LEOS, 2008, s. 53-54Konferensbidrag (Refereegranskat)
    Abstract [en]

    We demonstrate for the first time the phase-error compensation for a 20-GHz-spacing InP AWG with electrooptic phase shifters placed on 42 arrayed waveguides. The experiment results show successful phase control and 6-dB reduction of crosstalk.

  • 47. Jiang, W.
    et al.
    Okamoto, K.
    Soares, F. M.
    Olsson, Fredrik
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Lourdudoss, Sebastian
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Yoo, S. J. B.
    5 GHz channel spacing InP-based 32-channel Arrayed-Waveguide Grating2009Ingår i: OFC: 2009 Conference on Optical Fiber Communication, IEEE , 2009, s. 2660-2662Konferensbidrag (Refereegranskat)
    Abstract [en]

    We realize a 32-channel InP-based Arrayed-Waveguide Grating (AWG) with a 5-GHz channel spacing. The AWG shows approximately 14 dB excess-loss, 9 dB crosstalk, and 21 × 22 mm2 dimensions.

  • 48. Jiang, W.
    et al.
    Soares, F. M.
    Seo, S. W.
    Baek, J. H.
    Fontaine, N. K.
    Broeke, R. G.
    Cao, J.
    Yan, J.
    Okamoto, K.
    Olsson, Fredrik E.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Lourdudoss, Sebastian
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och Informationsteknik, IMIT.
    Pham, A.
    Yoo, S. J. B.
    A monolithic inp-based photonic integrated circuit for optical arbitrary waveform generation2008Konferensbidrag (Refereegranskat)
    Abstract [en]

    We demonstrate a compact monolithically-integrated InP optical arbitrary waveform generator, consisting of an arrayed waveguide grating pair with 10 GHz channel spacing, 10 high-speed optical amplitude modulators, and 10 high-speed optical phase modulators.

  • 49.
    Joharifar, Mahdieh
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Dely, H.
    Pang, Xiaodan
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Schatz, Richard
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Gacemi, D.
    Salgals, T.
    Udalcovs, Aleksejs
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Sun, Yan-Ting
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Fan, Yuchuan
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Zhang, L.
    Rodriguez, E.
    Spolitis, S.
    Bobrovs, V.
    Yu, Xianbin
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Lourdudoss, Sebastian
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Popov, Sergei
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Vasanelli, A.
    Ozolins, Oskars
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Sirtori, C.
    High-Speed 9.6-μm Long-Wave Infrared Free-Space Transmission With a Directly-Modulated QCL and a Fully-Passive QCD2023Ingår i: Journal of Lightwave Technology, ISSN 0733-8724, E-ISSN 1558-2213, Vol. 41, nr 4, s. 1087-1094Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Free-space optics (FSO) in the mid-infrared (mid-IR) contains rich spectral resources for future ultrahigh-speed wireless communications yet is currently under-exploited. Two atmospheric transmission windows at the mid-IR, namely, the mid-wave IR (MWIR, 3-5 μm) and the long-wave IR (LWIR, 8-12 μm), show great potential in supporting free-space communications for both terrestrial and space application scenarios. Particularly, the LWIR signal with a longer wavelength has high intrinsic robustness against aerosols' scattering and turbulence-induced scintillation and beam broadening effects, which are the main concerns hindering the wide deployment of practical FSO systems. In this context, high-bandwidth semiconductor-based mid-IR FSO transceivers will be desirable to meet the requirements of low energy consumption and small footprints for large-volume development and deployment. Quantum cascade devices, including quantum cascade lasers (QCLs) and quantum cascade detectors (QCDs), appear promising candidates to fulfill this role. In this work, we report a high-speed LWIR FSO transmission demonstration with a 9.6-μm directly-modulated (DM)-QCL and a fully passive QCD without any active cooling or bias voltage. Up to 8 Gb/s, 10 Gb/s, and 11 Gb/s signal transmissions are achieved when operating the DM-QCL at 10 °C, 5 °C, and 0 °C, respectively. These results indicate a significant step towards an envisioned fully-connected mid-IR FSO solution empowered by the quantum cascade semiconductor devices. 

  • 50.
    Joharifar, Mahdieh
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Han, Mengyao
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik. Beijing Jiaotong Univ, Inst Lightwave Technol, Key Lab All Opt Network & Adv Telecommun Network, Minist Educ, Beijing 100044, Peoples R China..
    Schatz, Richard
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Puerta, Rafael
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik. Ericsson AB, Ericsson Res, S-16483 Stockholm, Sweden..
    Sun, Yan-Ting
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Fan, Yuchuan
    RISE Res Inst Sweden, S-16440 Kista, Sweden..
    Maisons, Gregory
    mirSense, 2 Bd Thomas Gobert, Palaiseau, France..
    Abautret, Johan
    mirSense, 2 Bd Thomas Gobert, Palaiseau, France..
    Teissier, Roland
    mirSense, 2 Bd Thomas Gobert, Palaiseau, France..
    Zhang, Lu
    Zhejiang Univ, Coll Informat Sci & Elect Engn, Hangzhou 310027, Peoples R China.;Zhejiang Lab, Hangzhou 310027, Peoples R China..
    Spolitis, Sandis
    Riga Tech Univ, Inst Telecommun, LV-1048 Riga, Latvia.;Riga Tech Univ, Commun Technol Res Ctr, LV-1048 Riga, Latvia..
    Wang, Muguang
    Beijing Jiaotong Univ, Inst Lightwave Technol, Key Lab All Opt Network & Adv Telecommun Network, Minist Educ, Beijing 100044, Peoples R China..
    Bobrovs, Vjaceslavs
    Riga Tech Univ, Inst Telecommun, LV-1048 Riga, Latvia..
    Lourdudoss, Sebastian
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Yu, Xianbin
    Zhejiang Univ, Coll Informat Sci & Elect Engn, Hangzhou 310027, Peoples R China.;Zhejiang Lab, Hangzhou 310027, Peoples R China..
    Popov, Sergei
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Ozolins, Oskars
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik. RISE Res Inst Sweden, S-16440 Kista, Sweden.;Riga Tech Univ, Inst Telecommun, LV-1048 Riga, Latvia..
    Pang, Xiaodan
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik. RISE Res Inst Sweden, S-16440 Kista, Sweden.;Riga Tech Univ, Inst Telecommun, LV-1048 Riga, Latvia..
    8.1 Gbps PAM8 Long -Wave IR FSO Transmission using a 9.15-mu m Directly-Modulated QCL with an MCT Detector2023Ingår i: 2023 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXHIBITION, OFC, IEEE , 2023Konferensbidrag (Refereegranskat)
    Abstract [en]

    We experimentally demonstrate a Long-Wave IR FSO link with a 9.15-hm directly modulated quantum cascade laser at room temperature. Up to 8.1 Gb/s PAM8 transmission over 1.4 meter is achieved with a wideband MCT detector.

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