Change search
Refine search result
1 - 50 of 50
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the 'Create feeds' function.
  • 1.
    Aggerstam, Thomas
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Andersson, T.G.
    Holmström, Petter
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Jänes, Peter
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Liu, X. Y.
    Lourdudoss, Sebastian
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Thylén, Lars
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    GaN/AlN multiple quantum well structures grown by MBE on GaN templates for 1.55 mu m intersubband absorption2007In: Quantum Sensing and Nanophotonic Devices IV / [ed] Razeghi, M; Brown, GJ, 2007, Vol. 6479, p. 64791E-1-64791E-12Conference paper (Refereed)
    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. Andersson, T. G.
    et al.
    Liu, X. Y.
    Aggerstam, Thomas
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Holmström, Petter
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Lourdudoss, Sebastian
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Thylen, Lars
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Chen, Y. L.
    Hsieh, C. H.
    Lo, I.
    Macroscopic defects in GaN/AlN multiple quantum well structures grown by MBE on GaN templates2009In: Microelectronics Journal, ISSN 0026-2692, Vol. 40, no 2, p. 360-362Article in journal (Refereed)
    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.

  • 3.
    Berglind, Eilert
    et al.
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Holmström, Petter
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Thylén, Lars
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    On the Possibilities to Create a Negative Permittivity Metamaterial with Zero Imaginary Part of the Permittivity at a Specific Frequency-Electrical Network Theory Approach2012In: IEEE Journal of Quantum Electronics, ISSN 0018-9197, E-ISSN 1558-1713, Vol. 48, no 4, p. 507-511Article in journal (Refereed)
    Abstract [en]

    A permittivity function suggested in the literature describing a material that exhibits negative permittivity and no loss at a specific frequency (and losses at other frequencies) is analyzed using electrical network theory. An equivalent circuit of the polarization admittance consisting of RLC components is derived. Further, a proof is given showing that if the admittance is lossless at a specific frequency, then all components with losses (resistances) in the circuit have to be short circuited or blocked or virtually disconnected at this frequency by the use of ideal lossless resonant LC circuits. However, in the literature, inductors in metamaterials are associated with inherently lossy metal nanoparticles, hence invalidating the suggested permittivity function unless a lossless inductor at optical frequencies is found or proved possible.

  • 4. Bratkovsky, Alexander
    et al.
    Ponizovskaya, Ekaterina
    Wang, Shih-Yuan
    Holmström, Petter
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics.
    Thylén, Lars
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics.
    Fu, Ying
    KTH, School of Biotechnology (BIO), Theoretical Chemistry.
    Ågren, Hans
    KTH, School of Biotechnology (BIO), Theoretical Chemistry.
    A metal-wire/quantum-dot composite metamaterial with negative epsilon and compensated optical loss2008In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 93, no 19, p. 193106-Article in journal (Refereed)
    Abstract [en]

    Numerical simulations of a binary mixture of quantum dots exhibiting gain with silver nanorods are performed, showing the feasibility of lossless negative epsilon operation for realistic material structures and parameters.

  • 5.
    Holmstrom, Petter
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Thylen, Lars
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Bratkovsky, Alexander
    Composite metal/quantum-dot nanoparticle-array waveguides with compensated loss2010In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 97, no 7, p. 073110-Article in journal (Refereed)
    Abstract [en]

    We calculate the dispersion properties of waveguides composed of near-field-coupled arrays of metal-clad quantum dots (QDs). The high optical loss incurred by operating the metal shells close to resonance is mitigated by using optical gain in the QDs. A condition for achieving loss compensated operation is given based on realistic material parameters and neglecting inhomogeneous broadening. (C) 2010 American Institute of Physics. [doi:10.1063/1.3467845]

  • 6.
    Holmström, Petter
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Electroabsorption modulator using intersubband transitions in GaN-AlGaN-AlN step quantum wells2006In: IEEE Journal of Quantum Electronics, ISSN 0018-9197, E-ISSN 1558-1713, Vol. 42, no 7-8, p. 810-819Article in journal (Refereed)
    Abstract [en]

    We calculate the high-speed modulation properties of an electroabsorption modulator for lambda = 1.55 mu m based on Stark shifting an intersubband resonance in GaN-AlGaN-AlN step quantum wells. In a realistic simulation assuming an absorption linewidth Gamma = 100 meV we obtain an RC-limited electrical f(3dB) similar to 60 GHz at an applied voltage swing V-pp = 2.8 V. We also show that a small negative effective chirp parameter suitable for standard single-mode fiber is obtained and that the absorption is virtually unsaturable. The waveguide is proposed to be based on the plasma effect in order to simultaneously achieve a strong confinement of the optical mode, a low series resistance, and lattice-matched cladding and core waveguide layers. Extrapolated results reflecting the decisive dependence of the high-speed performance on the intersubband absorption linewidth Gamma are also given. At the assumed linewidth the modulation speed versus signal power ratio is on a par with existing lumped interband modulators based on the quantum confined Stark effect.

  • 7.
    Holmström, Petter
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Intersubband Electroabsorption Modulator2007In: Nitride Semiconductor Devices: Principles and Simulation / [ed] J. Piprek, Berlin: Wiley-VCH Verlagsgesellschaft, 2007, p. 253-277Chapter in book (Refereed)
  • 8.
    Holmström, Petter
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Jänes, Peter
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Ekenberg, Ulf
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Thylen, Lars
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Efficient electroabsorption for mid-infrared wavelengths using intersubband transitions2008In: PROCEEDINGS OF THE 17TH INTERNATIONAL VACUUM CONGRESS/13TH INTERNATIONAL CONFERENCE ON SURFACE SCIENCE/INTERNATIONAL CONFERENCE ON NANOSCIENCE AND TECHNOLOGY / [ed] Johansson LSO, Andersen JN, Gothelid M, Helmersson U, Montelius L, Rubel M, Setina J, Wernersson LE, Bristol: IOP PUBLISHING LTD , 2008, Vol. 100Conference paper (Refereed)
    Abstract [en]

    We have demonstrated efficient intersubband (IS) electroabsorption in InGaAs/InAlGaAs/InAlAs step quantum wells grown by metal-organic vapor phase epitaxy (MOVPE). An absorption modulation of 2300 cm(-1) at lambda=5.7 mu m due to Stark shift of the IS resonance was achieved with a low applied voltage swing of +/-0.5 V in a multipass waveguide structure. Two useful wavelength ranges of lambda approximate to 5.4-5.8 mu m and 6.3-6.6 mu m were obtained by considering the two flanks of the IS resonance. Based on the experimental results it is estimated that an electroabsorption modulator with a low peak-to-peak voltage of V-PP = 0.9 V can yield a modulation speed of f(3dB) = 120 GHz with the present material by using a strongly confining surface plasmon waveguide of 30 mu m length.

  • 9.
    Holmström, Petter
    et al.
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Jänes, Peter
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Ekenberg, Ulf
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Thylén, L.
    Design of intersubband optical modulators2002In: Proceedings of the 26th International Conference on the Physicsof Semiconductors (26th ICPS), Edinburgh, Scotland, 2002, 2002, p. P126-Conference paper (Refereed)
  • 10.
    Holmström, Petter
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Jänes, Peter
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Ekenberg, Ulf
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Thylén, Lars
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Efficient infrared electroabsorption with 1 V applied voltage swing using intersubband transitions2008In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 93, no 19, article id 191101Article in journal (Refereed)
    Abstract [en]

    We have demonstrated efficient intersubband electroabsorption in InGaAs/InAlGaAs/InAlAs step quantum wells grown by metal-organic vapor-phase epitaxy. An absorption modulation of 6 dB (Delta alpha=2300 cm(-1)) at lambda similar to 5.7 mu m due to Stark shift of the intersubband resonance was achieved at a low applied voltage swing of +/- 0.5 V in a multipass waveguide structure. The interface intermixing was estimated by comparing experimental and theoretical Stark shifts. It is predicted that the present material in a strongly confining surface plasmon waveguide can yield an electroabsorption modulator with a peak-to-peak voltage of V-pp=0.9 V and modulation speed of f(3dB)approximate to 130 GHz.

  • 11.
    Holmström, Petter
    et al.
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Jänes, Peter
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Ekenberg, Ulf
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Thylén, Lars
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Infrared modulator at 6 um with 1-V applied voltage swing using  intersubband transitions in step quantum wells grown by MOVPE2007Conference paper (Refereed)
  • 12.
    Holmström, Petter
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Jänes, Peter
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Ekenberg, Ulf
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Thylén, Lars
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Strong electroabsorption using intersubb and transitions in InGaAs/InAlGaAs/InAlAs step quantum wells2006In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118Article in journal (Other academic)
  • 13.
    Holmström, Petter
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Liu, X. Y.
    Uchida, H.
    Aggerstam, Thomas
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Kikuchi, A.
    Kishino, K.
    Lourdudoss, Sebastian
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Andersson, T.G.
    Thylén, Lars
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Intersubband photonic devices by group-III nitrides2007In: Optoelectronic Materials And Devices II / [ed] Nakano, Y, 2007, Vol. 6782, p. N7821-N7821Conference paper (Refereed)
    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).

  • 14.
    Holmström, Petter
    et al.
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Matsui, Satoshi
    Sophia University.
    Uchida, Hiroyuki
    Sophia University.
    Nakazato, Takuya
    Sophia University.
    Jänes, Peter
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Aggerstam, Tomas
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Kikuchi, Akihiko
    Sophia University.
    Kishino, Katsumi
    Sophia University.
    Electroabsorption modulator based on intersubband transitions in (Al)(Ga)N step quantum wells considering intermixing2005Conference paper (Refereed)
  • 15.
    Holmström, Petter
    et al.
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Thylen, Lars
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Bratkovsky, Alexander
    METAL-NANOSHELL/QUANTUM-DOT ARRAY WAVEGUIDES WITH COMPENSATED LOSS2010In: Journal of nonlinear optical physics and materials, ISSN 0218-8635, Vol. 19, no 4, p. 595-601Article in journal (Refereed)
    Abstract [en]

    Dispersion properties of nanoarray waveguides composed of near-field-coupled arrays of metal-clad quantum dots (QDs) are calculated. The high loss due to operation of the metal shells close to resonance is mitigated by using optical gain in the QDs. The conditions for achieving loss compensated operation are given, with realistic material parameters and neglecting inhomogeneous broadening.

  • 16.
    Holmström, Petter
    et al.
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Optics and Photonics, OFO.
    Thylén, Lars
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Optics and Photonics, OFO.
    Electro-optic switch based on near-field-coupled quantum dots2014In: Applied Physics A: Materials Science & Processing, ISSN 0947-8396, E-ISSN 1432-0630, Vol. 115, no 4, p. 1093-1101Article in journal (Refereed)
    Abstract [en]

    The propagation of exciton polaritons in near-field-coupled quantum-dot (QD) chains is modeled by a density-matrix formalism. It is shown that at least for low-temperature operation it is possible using electronically controlled switching by the quantum-confined Stark effect in such QD chains to rival and outperform room-temperature CMOS electronics in footprint and switch energy, though not in speed.

  • 17.
    Holmström, Petter
    et al.
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Thylén, Lars
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics.
    Bratkovsky, A.
    Dielectric function of quantum dots in the strong confinement regime2010In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 107, no 6Article in journal (Refereed)
    Abstract [en]

    The complex dielectric function of quantum dots (QDs) with a core-shell structure is modeled in the strong confinement regime. These results should be useful for the design of negative epsilon optical metamaterials, where the gain due to QDs could be an essential ingredient. Using the dielectric function it is also shown that conventional expressions for the gain substantially overestimate it for narrow linewidths.

  • 18.
    Holmström, Petter
    et al.
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101).
    Yuan, Jun
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101).
    Qiu, Min
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101).
    Thylén, Lars
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101).
    Bratkovsky, Alexander M.
    Hewlett-Packard Laboratories.
    Application of metal nanoparticle arrays as a metamaterial for nanooptical directional couplers2010Conference paper (Refereed)
  • 19.
    Holmström, Petter
    et al.
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101).
    Yuan, Jun
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101).
    Qiu, Min
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101).
    Thylén, Lars
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101).
    Bratkovsky, Alexander M.
    Hewlett-Packard Laboratories.
    Passive and active plasmonic nanoarray devices2011In: Metamaterials VI / [ed] Kuzmiak, Markos, Szoplik, SPIE - International Society for Optical Engineering, 2011, p. 80700T-1-80700T-6Conference paper (Refereed)
    Abstract [en]

    Metal nanoparticle arrays offer the possibility to considerably surpass the optical field confinement of silicon waveguides. The properties of directional couplers composed of such plasmonic nanoarrays are analyzed theoretically, while neglecting material losses. It is found that it is possible to generate very compact, submicron length, high fieldconfinement and functionality devices with very low switch energies. We further perform a study of spatial losses in Ag nanoparticle arrays by obtaining the group velocity and the lifetime of the surface plasmon polaritons. The losses are determined for different host permittivities, polarizations, and for spherical and spheroidal particles, with a minimum loss of 12 dB/μm. The possibilities to compensate the losses using gain materials, and the added noise associated with that, is briefly discussed.

  • 20.
    Holmström, Petter
    et al.
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101).
    Yuan, Jun
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101). Xidian University, China.
    Qiu, Min
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101).
    Thylén, Lars
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101). Hewlett-Packard Laboratories, United States.
    Bratkovsky, Alexander M.
    Hewlett-Packard Laboratories, United States.
    Theoretical study of nanophotonic directional couplers comprising near-field-coupled metal nanoparticles2011In: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 19, no 8, p. 7885-7893Article in journal (Refereed)
    Abstract [en]

    The properties of integrated-photonics directional couplers composed of near-field- coupled arrays of metal nanoparticles are analyzed theoretically. It is found that it is possible to generate very compact, submicron length, high field-confinement and functionality devices with very low switch energies. The analysis is carried out for a hypothetical lossless silver to demonstrate the potential of this type of circuits for applications in telecom and interconnects. Employing losses of real silver, standalone devices with the above properties are still feasible in optimized metal nanoparticle structures.

  • 21.
    Jänes, Peter
    et al.
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Holmström, Petter
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    High-speed optical modulator based on intersubband transitions in InGaAs/InAlAs/AlAsSb coupled quantum wells2003In: Conference Proceedings - International Conference on Indium Phosphide and Related Materials, 2003, p. 308-311Conference paper (Refereed)
    Abstract [en]

    We investigate theoretically an optical modulator based on intersubband transitions in InGaAs/InAlAs/AlAsSb coupled quantum wells with an operating wavelength of 1.55 mum. We show that such a modulator has the potential to outperform conventional electroabsorption and electro-optic modulators with a combination of high speed, moderate voltage swing, negative chirp and high saturation power. The modulator studied here is predicted to have a RC-limited speed of 90 GHz with 10 dB extinction ratio at a peak-to-peak voltage of 2.0 V.

  • 22.
    Jänes, Peter
    et al.
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Holmström, Petter
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Ekenberg, Ulf
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    A high-speed intersubband modulator based on quantum interference in double quantum wells2002In: IEEE Journal of Quantum Electronics, ISSN 0018-9197, E-ISSN 1558-1713, Vol. 38, no 2, p. 178-184Article in journal (Refereed)
    Abstract [en]

    Calculations on a modulator based on quantum interference in AlGaAs/GaAs asymmetric double quantum wells (QWs) are performed. The modulation of the absorption is based on the anti-crossing behavior of the two lowest states in the coupled wells. At anti-crossing, the oscillator strengths of the transitions from these two lowest states to a higher state are changed in opposite directions. The width of the barrier between the wells should be thick enough to allow a large change in oscillator strength with applied field, yet thin enough so that the absorption peaks of the transitions are resolved. The QWs are designed so that one absorption peak has only a small energy shift for the transition used for modulation while the absorption varies rapidly with the applied voltage. A complete structure including a surface plasmon waveguide is proposed enabling calculations of modal absorption. Parameters important for the performance of the modulator are then determined. An extinction ratio of 10 dB at a wavelength of 8.4 mum is predicted for a device length of 18 mum and a peak-to-peak voltage of 0.9 V. The resistance-capacitance-limited 3-dB bandwidth is 130 GHz. The predicted performance compares very favorably with present interband modulators based on the quantum-confined Stark effect.

  • 23. Liu, X. Y.
    et al.
    Fälth, J. F.
    Andersson, T. G.
    Holmström, Petter
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Jänes, Peter
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Ekenberg, Ulf
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Thylén, Lars
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Structural and optical properties of GaN/AlN multiple quantum wells for intersubband applications2005In: Journal of Crystal Growth, ISSN 0022-0248, E-ISSN 1873-5002, Vol. 278, no 1-4, p. 397-401Article in journal (Refereed)
    Abstract [en]

    GaN/AIN multiple quantum well structures of 1, 5 and 20 periods were grown by molecular beam epitaxy (MBE). To investigate structural parameters, symmetrical scan (0002) and reciprocal space mapping in the vicinity of the GaN (10 15) plane were made by X-ray diffraction (XRD). The layer thickness, composition and relaxation were determined and gave good agreement with simulated results. The 20 period multiple quantum well (MQW) sample exhibited an intersubband resonance at 360 meV, which corresponds well to the structure data determined by XRD.

  • 24. Liu, X. Y.
    et al.
    Holmström, Petter
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Jänes, Peter
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Thylén, Lars
    KTH, School of Information and Communication Technology (ICT).
    Andersson, T.G.
    Intersubband absorption at 1.5-3.5 µm in GaN/AlN multiple quantum wells grown by molecular beam epitaxy on sapphire2007In: Physica status solidi, ISSN 0370-1972, Vol. 244, no 8, p. 2892-2905Article in journal (Refereed)
    Abstract [en]

    Ten and twenty period multiple quantum well structures with 1.5-5.4 nm GaN wells and 1.2-5.1 nm AlN barriers were grown on sapphire by molecular beam epitaxy. Layer thicknesses were determined by X-ray diffraction measurements and simulations. Reciprocal space mapping showed that the relaxation of the quantum well layers was independent of the buffer layer thickness. Intersubband absorption was observed by Fourier transform infrared spectroscopy at λ ∼ 1.5-3.5 μm. Monolayer fluctuations in the quantum well width induced multiple peaks in spectra, which were well fitted to Lorentzian peaks of only 57 meV linewidth. Samples were very homogeneous as the absorption peak energy varied less than 1% along ∼4 cm on 2 inch wafers. The intersubband transition energies were calculated considering the conduction-band nonparabolicity, built-in fields, strain, and many-body effects. The calculation and comparison to the fitted Lorentzian peak energies indicated a moderate blueshift due to many-body effects. It was shown by both experiments and calculations that the AlN barrier width affects the intersubband transition energy.

  • 25. Liu, X.Y
    et al.
    Aggerstam, Thomas
    KTH, School of Information and Communication Technology (ICT), Material Physics, Semiconductor Materials, HMA.
    Jänes, Peter
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Holmström, Petter
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Lourdudoss, Sebastian
    KTH, School of Information and Communication Technology (ICT), Material Physics, Semiconductor Materials, HMA.
    Thylén, Lars
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics.
    Andersson, T. G.
    Investigation of intersubband absorption of GaN/AlN multiple quantum wells grown on different substrates by molecular beam epitaxy2007In: Journal of Crystal Growth, ISSN 0022-0248, E-ISSN 1873-5002, Vol. 301, no SPEC. ISS., p. 301-302Article in journal (Refereed)
    Abstract [en]

    Ten period GaN/AlN multiple quantum well (MQW) structures were grown by plasma-assisted molecular beam epitaxy (MBE) on sapphire substrates and metal-organic vapour-phase epitaxy (MOVPE)-grown GaN templates. Samples were investigated by high-resolution X-ray diffraction (HR-XRD) and Fourier transform infrared (FT-IR) spectroscopy. Intersubband (IS) absorbances and FWHM of IS absorption peaks indicated that samples grown on the GaN templates had better characteristics, resulting in a FWHM as low as 93 meV at a peak energy of 700 meV.

  • 26.
    Matsui, Satoshi
    et al.
    Sophia University.
    Ishii, Yohei
    Sophia University.
    Morita, Takayuki
    Sophia University.
    Holmström, Petter
    Sophia University.
    Sekiguchi, Hiroto
    Sophia University.
    Kikuchi, Akihiko
    Sophia University.
    Kishino, Katsumi
    Sophia University.
    All-optical modulation using intersubband transitions at 1.55 mu m in GaN/AlN multiple quantum well2005In: Physica Status Solidi. C, Current topics in solid state physics, ISSN 1610-1634, E-ISSN 1610-1642, Vol. 2, no 7, p. 2748-2752Article in journal (Refereed)
    Abstract [en]

    All-optical modulation using intersubband transition (ISBT) resonant light (wavelength of 1.55 μm) and induced by UV interband transition (IBT) resonant light (325 nm or 213 nm) was demonstrated in a GaN/AlN multiple quantum well (MQW) waveguide device. The modulation was selective and occurred only for p-polarized ISBT resonant light in accordance with ISBT characteristics. An IBT relaxation time of 1.5 ns was obtained by fitting the experimental results with a three-level model, taking into consideration the valence band, the conduction band and the trap-state.

  • 27. Naruse, Makoto
    et al.
    Akahane, Kouichi
    Yamamoto, Naokatsu
    Holmström, Petter
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Optics and Photonics, OFO.
    Thylén, Lars
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Optics and Photonics, OFO. Laboratory of Photonics and Microwave Engineering.
    Huant, Serge
    Ohtsu, Motoichi
    Analysis of optical near-field energy transfer by stochastic model unifying architectural dependencies2014In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 115, no 15, p. 154306-Article in journal (Refereed)
    Abstract [en]

    We theoretically and experimentally demonstrate energy transfer mediated by optical near-field interactions in a multi-layer InAs quantum dot (QD) structure composed of a single layer of larger dots and N layers of smaller ones. We construct a stochastic model in which optical near-field interactions that follow a Yukawa potential, QD size fluctuations, and temperature-dependent energy level broadening are unified, enabling us to examine device-architecture-dependent energy transfer efficiencies. The model results are consistent with the experiments. This study provides an insight into optical energy transfer involving inherent disorders in materials and paves the way to systematic design principles of nanophotonic devices that will allow optimized performance and the realization of designated functions.

  • 28.
    Naruse, Makoto
    et al.
    Natl Inst Informat & Commun Technol, Tokyo, Japan .
    Holmström, Petter
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Kawazoe, Tadashi
    Univ Tokyo, Tokyo, Japan .
    Akahane, Kouichi
    Natl Inst Informat & Commun Technol, Tokyo, Japan .
    Yamamoto, Naokatsu
    Natl Inst Informat & Commun Technol, Tokyo, Japan ; Univ Tokyo, Tokyo, Japan .
    Thylén, Lars
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Ohtsu, Motoichi
    Univ Tokyo, Tokyo, Japan .
    Energy dissipation in energy transfer mediated by optical near-field interactions and their interfaces with optical far-fields2012In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 100, no 24, p. 241102-Article in journal (Refereed)
    Abstract [en]

    We theoretically and experimentally evaluated energy dissipation of nanophotonic devices based on energy transfer via near-field interactions and their interfaces with optical far-fields. The lower bound is about 10(4) times more energy-efficient than electronic devices. We also examined some fundamental differences between near-field-mediated optical energy transfer logic and electrical logic in terms of energy dissipation.

  • 29. Naruse, Makoto
    et al.
    Hori, Hirokazu
    Kobayashi, Kiyoshi
    Holmström, Petter
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Thylén, Lars
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Ohtsu, Motoichi
    Lower bound of energy dissipation in optical excitation transfer via optical near-field interactions2010In: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 18, no 23, p. A544-A553Article in journal (Refereed)
    Abstract [en]

    We theoretically analyzed the lower bound of energy dissipation required for optical excitation transfer from smaller quantum dots to larger ones via optical near-field interactions. The coherent interaction between two quantum dots via optical near-fields results in unidirectional excitation transfer by an energy dissipation process occurring in the larger dot. We investigated the lower bound of this energy dissipation, or the intersublevel energy difference at the larger dot, when the excitation appearing in the larger dot originated from the excitation transfer via optical near-field interactions. We demonstrate that the energy dissipation could be as low as 25 mu eV. Compared with the bit flip energy of an electrically wired device, this is about 10(4) times more energy efficient. The achievable integration density of nanophotonic devices is also analyzed based on the energy dissipation and the error ratio while assuming a Yukawa-type potential for the optical near-field interactions.

  • 30.
    Ohashi, Tetsuo
    et al.
    Sophia University.
    Holmström, Petter
    Sophia University.
    Kikuchi, Akihiko
    Sophia University.
    Kishino, Katsumi
    Sophia University.
    High-structural quality InN/In0.75Ga0.25N Multiple Quantum Wells Grown by Molecular Beam Epitaxy2006In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 89, no 4, p. 041907-1-041907-3Article in journal (Refereed)
    Abstract [en]

    InN/In0.75Ga0.25N multiple quantum wells (MQWs) were grown by rf plasma-assisted molecular beam epitaxy. The high-resolution transmission electron microscope and x-ray diffraction measurements showed evidence of growth of atomically smooth and sharp interface and good periodicity. Room-temperature photoluminescence emissions from InN quantum wells were observed at the wavelength range from 1.59 to 1.95 um by changing the well thickness. The unstrained valence band offset of InN/GaN was estimated to be ΔEv=0.9 eV by comparing the experimental transition wavelengths of the MQWs and a theoretical calculation considering strain effects and built-in, mainly piezoelectric, fields.

  • 31.
    Thylen, Lars
    et al.
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Holmström, Petter
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Bratkovsky, Alexander
    Li, Jingjing
    Wang, Shih-Yuan
    Limits on Integration as Determined by Power Dissipation and Signal-to-Noise Ratio in Loss-Compensated Photonic Integrated Circuits Based on Metal/Quantum-Dot Materials2010In: IEEE Journal of Quantum Electronics, ISSN 0018-9197, E-ISSN 1558-1713, Vol. 46, no 4, p. 518-524Article in journal (Refereed)
    Abstract [en]

    We analyze the power dissipation that is associated with using the gain of an embedded medium (quantum dots) to overcome the losses inherent in plasmonics systems employed to produce a negative dielectric constant for nanophotonics circuits. This power dissipation is primarily due to the dissipative losses in the metal structures and Auger recombination in the quantum dots. The impact of amplifier mediated signal-to-noise ratio (SNR) degradation and its effect on integration is analyzed, and a tradeoff between low power dissipation and SNR is quantified.

  • 32.
    Thylén, Lars
    et al.
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Arve, Per
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Hessmo, Björn
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Holmström, Petter
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Jänes, Peter
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Karlsson, Anders
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Qiu, Min
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Progress in opto-electronic devices2004In: / [ed] Lam, CF; Fan, CC; Hanik, N; Oguchi, K, BELLINGHAM: SPIE-INT SOC OPTICAL ENGINEERING , 2004, Vol. 5280Conference paper (Refereed)
    Abstract [en]

    We discuss the statu,, of photonics technology and review its possible evolution by way of several representative examples of emerging research areas, which could have a significant impact over a long-term, say 10-year perspective. The selected areas are considered potentially capable of providing the quantum leap progress necessary to solve some of the shortcomings of current photonics technology.

  • 33.
    Thylén, Lars
    et al.
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Holmström, Petter
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Passive and Active Integrated Nanophotonics Devices and Circuits2010Conference paper (Refereed)
  • 34.
    Thylén, Lars
    et al.
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101). Hewlett-Packard Laboratories, Palo Alto, CA 94304, United States .
    Holmström, Petter
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101).
    Plasmonics for Signal Processing2011In: 2011 Optical Fiber Communication Conference and Exposition and the National Fiber Optic Engineers Conference, OFC/NFOEC 2011, WASHINGTON: Optical Society of America , 2011Conference paper (Refereed)
    Abstract [en]

    We review some of the issues involved in using different plasmonic guided-wave structures for modulation, switching and filtering.

  • 35.
    Thylén, Lars
    et al.
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101).
    Holmström, Petter
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101).
    Berglind, Eilert
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101).
    Yan, Min
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101).
    Dai, Daoxin
    Centre for Optical and Electromagnetic Research, State Key Laboratory for Modern Optical Instrumentation, Zhejiang University.
    Wosinski, Lech
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101).
    Bratkovsky, Alex
    Complementing or replacing silicon and III–Vs: The role of plasmonics and novel materials in future integrated photonics for telecom and interconnects2011In: 2011 13th International Conference on Transparent Optical Networks, ICTON 2011, IEEE Communications Society, 2011Conference paper (Refereed)
    Abstract [en]

    Integrated photonics has largely been based on silicon/silica and III-Vs in recent times. Both have their advantages and disadvantages, but neither seem capable of supporting a further significant reduction of device footprint to sustain the exponential decrease of this important parameter that we have witnessed since decades. The talk will analyze different aspects of plasmonics from this and a functionality point of view and further discuss some possible alternative materials.

  • 36.
    Thylén, Lars
    et al.
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics. KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Holmström, Petter
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Berglind, Eilert
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Yan, Min
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Dai, Daoxin
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Wosinski, Lech
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics. KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Bratkovsky, Alex
    Metamaterials- and Nanotechnology-based Low Power and Small Footprint Integrated Photonics2011In: 2011 IEEE Photonics Conference (PHO), IEEE Communications Society, 2011, p. 537-538Conference paper (Refereed)
    Abstract [en]

    Integrated nanophotonics has shown a remarkable development in recent years and can find applications in virtually all fields of photonics, though its predominant focus has so far been in telecom and lately computer interconnects. This progress has primarily been based on nanoand ΠI-V technology development, the introduction of silicon technology, with larger refractive index contrast than previously available, as well as subwavelength plasmonics structures. For the latter, a main problem, especially for ICT applications, has been the large optical loss associated with deep subwavelength confinement, as in this paper.

  • 37.
    Thylén, Lars
    et al.
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Holmström, Petter
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Bratkovsky, Alexander M.
    Hewlett-Packard Laboratories.
    Loss compensated photonic integrated circuits based on metal/quantum dot materials: Different structures and their power dissipation2009In: 2009 International Nano-Optoelectronics Workshop (iNOW), 2009, p. 105-106Conference paper (Refereed)
    Abstract [en]

    We analyze different loss compensated metal/quantum dot based materials and waveguide structures.

  • 38.
    Thylén, Lars
    et al.
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics.
    Holmström, Petter
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics.
    Wosinski, Lech
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics.
    Low Power Nanophotonics and its Applications in Data Centers2014Conference paper (Refereed)
    Abstract [en]

    The evolution of future Data Centers requires novel means of information transmission due in part to the energy dissipated in the transport of information. Photonics in the form of active optical cables is used for both interrack as well as intra-rack connections. However, due to the superior bandwidth-density properties of photonics over copper based transmission, photonics is now being considered for inter-chip and even intra-chip interconnects. This requires novel approaches to create smaller (nanoscale), lower power dissipation functional devices in the transmission fabric, a development that could also be useful for a range of other applications. The current status as well as the prospects to achieve these ends and to take the next quantum leap in integrated nanophotonics are discussed.

  • 39.
    Thylén, Lars
    et al.
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Optics and Photonics, OFO. KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Holmström, Petter
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Optics and Photonics, OFO.
    Wosinski, Lech
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Optics and Photonics, OFO. KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Very-low-power and footprint integrated photonic modulators and switches for ICT2013In: Optoelectronic Integrated Circuits XV, SPIE - International Society for Optical Engineering, 2013, p. 862805-Conference paper (Refereed)
    Abstract [en]

    The current development in photonics for communications and interconnects pose increasing requirements on reduction of footprint, power dissipation and cost, as well as increased bandwidth. Integrated nanophotonics has been viewed as one solution to this, capitalizing on development in nanotechnology as such as well as on increased insights into light matter interaction on the nanoscale. The latter can be exemplified by plasmonics and low-dimensional semiconductors such as quantum dots (QDs). In this scenario the development of better electrooptic materials is also of great importance, the electrooptic polymers being an example, since they potentially offer improved properties for optical phase modulators in terms of power and probably cost and general flexibility. Phase modulators are essential for e. g. the rapidly developing advanced modulation formats for telecom, since phase modulation basically can generate any type of modulation. The electrooptic polymers, e. g. in combination with plasmonics nanoparticle array waveguides or nanostructured hybrid plasmonic media can theoretically give extremely compact and low power dissipation modulators, still to be demonstrated. The low-dimensional semiconductors, e. g. in the shape of QDs, can be employed for modulation or switching functions, offering possibilities in the future for scaling to 2 or 3 dimensions for advanced switching functions. In both the plasmonics and QD cases, nanosizing and low power dissipation are generally due to near-field interactions, albeit being of different physical origin in the two cases. A comparison of all-optical and electronically controlled switching is given.

  • 40.
    Thylén, Lars
    et al.
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Optics and Photonics, OFO.
    Holmström, Petter
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Optics and Photonics, OFO.
    Wosinski, Lech
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Optics and Photonics, OFO.
    Jaskorzynska, Bozena
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Optics and Photonics, OFO.
    Naruse, Makoto
    National Institute of Information and Communications Technology, , 4-2-1 Nukui-kita, Koganei, Tokyo, Japan 184-8795.
    Kawazoe, Tadashi
    School of Engineering, The University of Tokyo.
    Yan, Min
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Optics and Photonics, OFO.
    Fiorentino, M.
    Westergren, Urban
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Optics and Photonics, OFO.
    Nanophotonics for Low-Power Switches2013In: Optical FiberTelecommunications VIA: Components and Subsystems / [ed] Ivan Kaminow, Tingye Li and Alan Willner, Elsevier, 2013, p. 205-241Chapter in book (Other academic)
    Abstract [en]

    This chapter treats several approaches for employing nanophotonics or near-nanophotonics concepts to create low-power switches. The partly interrelated issues of low power dissipation and small device footprint are elucidated and figures of merit for switches formulated. Both optically and electronically controlled optical switches are treated and the crucial role of material development emphasized, illustrated by several examples, including both theoretical analysis of switch concepts and experimentally realized switches. Thus, electronically controlled switches based on hybrid, metamaterial and nanoparticle plasmonics, electrooptic polymers as well as switches based on silicon and photonic crystals are discussed. The all-optical switches focus on third-order nonlinear effects and carrier-induced refractive-index changes in III-V materials, as well as on emerging concepts of near-field-coupled quantum-dot switches. A brief comparison to electronic switches is done.

  • 41.
    Thylén, Lars
    et al.
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Optics and Photonics, OFO. KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Holmström, Petter
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Optics and Photonics, OFO.
    Wosinski, Lech
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Optics and Photonics, OFO. KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Lourdudoss, Sebastian
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA.
    Low-power nanophotonics: Material and device technology2013In: Integrated Optics: Physics And Simulations, SPIE - International Society for Optical Engineering, 2013, p. 87810Q-Conference paper (Refereed)
    Abstract [en]

    Development in photonics for communications and interconnects pose increasing requirements on reduction of footprint, power dissipation and cost, as well as increased bandwidth. Nanophotonics integrated photonics has been viewed as a solution to this, capitalizing on development in nanotechnology and an increased understanding of light matter interaction on the nanoscale. The latter can be exemplified by plasmonics and low dimensional semiconductors such as quantum dots (QDs). In this scenario the development of improved electrooptic materials is of great importance, the electrooptic polymers being an example, since they potentially offer superior properties for optical phase modulators in terms of power and integratability. Phase modulators are essential for e. g. the rapidly developing advanced modulation formats, since phase modulation basically can generate any type of modulation. The electrooptic polymers, in combination with plasmonics nanoparticle array waveguides or nanostructured hybrid plasmonic media can give extremely compact and low power dissipation modulators. Low-dimensional semiconductors, e. g. in the shape of QDs, can be employed for modulation or switching functions, offering possibilities for scaling to 2 or 3 dimensions for advanced switching functions. In both the high field confinement plasmonics and QDs, the nanosizing is due to near-field interactions, albeit being of different physical origin in the two cases. Epitaxial integration of III-V structures on Si plays an important role in developing high-performance light sources on silicon, eventually integrated with silicon electronics. A brief remark on all-optical vs. electronically controlled optical switching systems is also given.

  • 42.
    Thylén, Lars
    et al.
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Holmström, Petter
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Yan, Min
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Berglind, Eilert
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Wosinski, Lech
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Dai, Daoxin
    Bratkovsky, Alex
    Integrated photonics for interconnect: Silicon photonics,  plasmonics or something else2011Conference paper (Refereed)
  • 43.
    Thylén, Lars
    et al.
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Holmström, Petter
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Yan, Min
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Qiu, Min
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Dai, Daoxin
    Wosinski, Lech
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Densely integrated photonics circuits beyond silicon: Prospects, applications and power dissipation issues2011Conference paper (Refereed)
    Abstract [en]

    We analyze the possibility of using different plasmonic based waveguide devices for functions such as switching, modulation and filtering in photonic integrated circuits (PICs). Conclusions regarding the impact and remedies of Joule losses are given.

  • 44.
    Thylén, Lars
    et al.
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101). Hewlett-Packard Laboratories, Palo Alto, United States .
    Holmström, Petter
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101).
    Yuan, Jun
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101).
    Qiu, Min
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101).
    Bratkovsky, A. M.
    Integrated photonics in the future: Silicon, plasmonics or something else?2010In: 2010 Asia Communications and Photonics Conference and Exhibition, ACP 2010, 2010, p. 485-486Conference paper (Refereed)
  • 45.
    Thylén, Lars
    et al.
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics.
    Marcinkevicius, Saulius
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics.
    Holmström, Petter
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics.
    Nanophotonics: A tutorial2012In: Technical Digest - 2012 17th Opto-Electronics and Communications Conference, OECC 2012, 2012, p. 224-225Conference paper (Refereed)
    Abstract [en]

    Nanophotonics has received much attention in recent years, fuelled by general interest and progress in nanotechnology but also by rapid advances in photonics technology. The tutorial will cover basics and applications of nanophotonics.

  • 46.
    Thylén, Lars
    et al.
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Westergren, Urban
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Holmström, Petter
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Schatz, Richard
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Jänes, Peter
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Recent developments in high-speed optical modulators2008In: Optical Fiber Telecommunications V: A: Components and subsystems / [ed] I. P. Kaminow, T. Li, A. E. Willner, London: Academic Press, 2008, p. 183-220Chapter in book (Refereed)
  • 47.
    Uchida, Hiroyuki
    et al.
    Sophia University.
    Matsui, Satoshi
    Sophia University.
    Holmström, Petter
    Sophia University.
    Kikuchi, Akihiko
    Sophia University.
    Kishino, Katsumi
    Sophia University.
    Room-temperature operation of 1.55 um wavelength-range GaN/AlN quantum well intersubband photodetectors2005In: IEICE Electronics Express, ISSN 1349-2543, Vol. 2, no 22, p. 566-571Article in journal (Refereed)
    Abstract [en]

    The room-temperature operation of a GaN/AlN quantum well infrared photodetector (QWIP) using the intersubband transition (ISBT) in a GaN/AlN multiple quantum well (MQW) was demonstrated for the first time. The GaN/AlN QWIP was operated under DC biasing with a vertically conductive geometry to the MQW layer. A clear photoinduced response was observed for P polarized 1.47µm light irradiation. Dependencies of the photoresponse on the applied DC bias voltage, and the polarization and wavelength of incident light were evaluated for the GaN/AlN QWIP. The maximum responsivity was estimated to be 0.11mA/W for a DC bias of 15V at room temperature.

  • 48. Wang, J.
    et al.
    Guan, X.
    He, Y.
    Shi, Yaocheng
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP. Centre for Optical and Electromagnetic Research, State Key Laboratory for Modern Optical Instrumentation, Zhejiang University, Zijingang Campus, China.
    Wang, Zhechao
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP. Centre for Optical and Electromagnetic Research, State Key Laboratory for Modern Optical Instrumentation, Zhejiang University, Zijingang Campus, China .
    He, Sailing
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP. Centre for Optical and Electromagnetic Research, State Key Laboratory for Modern Optical Instrumentation, Zhejiang University, Zijingang Campus, China .
    Holmström, Petter
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101). KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Wosinski, Lech
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101). KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Thylén, Lars
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101). KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Dai, Daoxin
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Sub-μm2 power splitters by using silicon hybrid plasmonic waveguides2011In: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 19, no 2, p. 838-847Article in journal (Refereed)
    Abstract [en]

    Nano-scale power splitters based on Si hybrid plasmonic waveguides are designed by utilizing the multimode interference (MMI) effect as well as Y-branch structure. A three-dimensional finite-difference time-domain method is used for simulating the light propagation and optimizing the structural parameters. The designed 1×2 50:50 MMI power splitter has a nano-scale size of only 650 nm×530 nm. The designed Y-branch power splitter is also very small, i.e., about 900 nm×600 nm. The fabrication tolerance is also analyzed and it is shown that the tolerance of the waveguide width is much larger than±50 nm. The power splitter has a very broad band of over 500 nm. In order to achieve a variable power splitting ratio, a 2×2 two-mode interference coupler and an asymmetric Y-branch are used and the corresponding power splitting ratio can be tuned in the range of 97.1%:2.9%-1.7%:98.3% and 84%:16%-16%:84%, respectively. Finally a 1×4 power splitter with a device footprint of 1.9 μm×2.6 μm is also presented using cascaded Y-branches.

  • 49.
    Wang, Zhechao
    et al.
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Dai, Daoxin
    Shi, Yaocheng
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Somesfalean, Gabriel
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Holmström, Petter
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101).
    Thylén, Lars
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101). KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    He, Sailing
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Wosinski, Lech
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101). KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Experimental Realization of a Low-loss Nano-scale Si Hybrid Plasmonic Waveguide2011In: 2011 OPTICAL FIBER COMMUNICATION CONFERENCE AND EXPOSITION (OFC/NFOEC) AND THE NATIONAL FIBER OPTIC ENGINEERS CONFERENCE, Washington: Optical Society of America, 2011Conference paper (Refereed)
    Abstract [en]

    A novel hybrid plasmonic waveguide with nano-scale confinement, consisting of a metal layer separated from a SOI nano-rib by a thin silica layer has been realized. The loss of 0.01dB/mu m allows for ultra-high density photonic integration.

  • 50.
    Westergren, Urban
    et al.
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics. KTH, School of Information and Communication Technology (ICT), Centres, Kista Photonics Research Center, KPRC.
    Yu, Yichuan
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT. KTH, School of Information and Communication Technology (ICT), Centres, Kista Photonics Research Center, KPRC.
    Jänes, Peter
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP. KTH, School of Information and Communication Technology (ICT), Centres, Kista Photonics Research Center, KPRC.
    Holmström, Petter
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP. KTH, School of Information and Communication Technology (ICT), Centres, Kista Photonics Research Center, KPRC.
    Thylén, Lars
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT. KTH, School of Information and Communication Technology (ICT), Centres, Kista Photonics Research Center, KPRC.
    Efficient and compact light-intensity modulators for high frequencies and high bitrates2006In: ICTON 2006: 8th International Conference on Transparent Optical Networks, Vol 2, Proceedings: ESPC, NAON / [ed] Marciniak, M, 2006, p. 142-145Conference paper (Refereed)
    Abstract [en]

    Electroabsorption modulators (EAM) based on quantum-confined Stark effect (QCSE) in multiple-quantum wells (MQW) have been demonstrated to provide high-speed, low drive voltage, and high extinction ratio. They are compact in size and can be monolithically integrated with source lasers. In order to achieve both high speed and low drive-voltage operation, travelling-wave (TW) electrode structures can be used for EAMs. Modulation bandwidths of 100 GHz (-3 dBe) have been accomplished and transmission at 80 Gbit/s with non-return-to-zero (NRZ) code has been demonstrated for InP-based TWEAMs, indicating the possibility of reaching speeds of IOOGbit/s and beyond. In order to further increase the efficiency and reduce the drive voltage, MQW structures using intersubband (IS) instead of interband (QCSE) absorption are being investigated. Materials systems with large conduction band offset, such as GaN/Al(Ga)N or InGaAs/AlAsSb, are required for IS modulators. Critical for the performance of IS modulators is the linewidth of the absorption peak, hence IS modulators have the potential to outperform interband modulators given that a sufficiently high material quality can be achieved.

1 - 50 of 50
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf