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  • 1.
    Anand, Srinivasan
    et al.
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Qiu, Min
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Mulot, Mikael
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Swillo, Marcin
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Jaskorzynska, Bozena
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Karlsson, Anders
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    High aspect ratio etching and characterization of 2D-photonic crystals in InP/InGaAsP/InP heterostructures2004In: Photonics: Design, Technology, And Packaging / [ed] Jagadish, C; Choquette, KD; Eggleton, BJ; Nener, BD; Nugent, KA, SPIE - International Society for Optical Engineering, 2004, 78-89 p.Conference paper (Refereed)
    Abstract [en]

    We report on the fabrication and characterization of 2D photonic crystals (PhCs) in InP/InGaAsP/InP heterostructures. It is demonstrated that Ar/C12 based chemically assisted ion beam etching (CAIBE) is a very promising method to obtain high aspect ratio etching of PhCs in the InP-based materials. With this process, it is possible to obtain PC-holes as deep as 3 microns even for feature (PhC-hole) sizes as small as 200-250 nm. The optical characteristics of the fabricated PhC-based elements/devices such as line-defect waveguides, in-plane resonant cavities and drop-filter based on contra-directional coupling will be reported. The devices were measured using end-fire coupling and the obtained results were simulated using the 2D finite difference time domain (FDTD) method including an effective loss-approximation. The etched PhC-waveguides show low transmission losses, less than 1 dB/100 mum. A quality factor of 400 for a 6 micron long cavity with 6-hole mirrors is obtained. Finally, drop-functionality in a PhC-based filter using contra-directional coupling is demonstrated.

  • 2. Benisty, H.
    et al.
    Olivier, S.
    Weisbuch, C.
    Agio, M.
    Kafesaki, M.
    Soukoulis, C. M.
    Qiu, Min
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Swillo, Marcin
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Karlsson, Anders
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Jaskorzynska, Bozena
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Talneau, A.
    Moosburger, J.
    Kamp, M.
    Forchel, A.
    Ferrini, R.
    Houdre, R.
    Oesterle, U.
    Models and measurements for the transmission of submicron-width waveguide bends defined in two-dimensional photonic crystals2002In: IEEE Journal of Quantum Electronics, ISSN 0018-9197, E-ISSN 1558-1713, Vol. 38, no 7, 770-785 p.Article in journal (Refereed)
    Abstract [en]

    One of the essential building-blocks of miniature photonic crystal (PC)-based photonic integrated circuits (PICs) is the sharp bend. Our group has focused on the 2-D photonic crystal based on a triangular lattice of holes perforating a standard heterostructure. The latter, GaAlAs-based or InP-based, is vertically a monomode waveguide. We consider essentially one or two 60 bends defined by one to five missing rows, spanning both cases of monomode and multimode channel waveguides. From intensive modeling and various experimental measurements (both on GaAs and InP), we point out the origin of the present level of bend insertion losses and discuss the merits of the many roads open for improved design.

  • 3.
    Dainese, Matteo
    et al.
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Swillo, Marcin
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Thylén, Lars
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Qiu, Min
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Wosinski, Lech
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Jaskorzynska, Bozena
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Shushunova, V.
    Belarussian Stt. Univ. Info./R., Minsk.
    Narrow band coupler based on one-dimensional Bragg reflection waveguide2003In: 2003 Optical Fiber Communication Conference: Altanta, Georgia, 2003, 44-46 p.Conference paper (Refereed)
    Abstract [en]

    A new configuration based on the coupling between a conventional low loss, weakly guiding channel waveguide and a Bragg reflection waveguide (BRW) was discussed. The strong difference between the dispersion of a Bragg reflection waveguide and a channel waveguide was used to create a narrow band coupler. The two-dimensional analysis of the BRW was generally based on the transfer matrix method. The structure consisted of a weakly guiding conventional Ge-doped silica waveguide on the top of which a BRW was stacked. The number of periods in the mirror between the BRW and the silica waveguide affected the coupling length and ultimately the bandwidth.

  • 4. Fernando, H. N. J.
    et al.
    Canning, J.
    Wosinski, Lech
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Jaskorzynska, Bozena
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Dainese, M.
    Characterization of ultra-violet-induced changes in planar waveguides2003In: Journal of Optics. A, Pure and applied optics, ISSN 1464-4258, E-ISSN 1741-3567, Vol. 5, no 4, 335-340 p.Article in journal (Refereed)
    Abstract [en]

    A simple, low-cost spectrophotometer system operating in reflection absorption mode is used to characterize changes in refractive index and thickness of thin films under 193 nm irradiation. The results indicate overall dilation of the glass and are confirmed by additional surface topographic measurements. We also show that in addition to the net relaxation from laser annealing of the interface, in germanosilicate samples local compaction takes place. Since the net relaxation is triggered by remote interactions, it is not spatially confined to the laser-irradiated area. However, a local positive index change is observed. These results are in agreement with previous hypotheses put forward to explain planar waveguide negative index changes. They also bring to attention the great care necessary in both conducting and interpreting measurements that do not take into account spatial variations arising from the combination of remote and local triggers of both index and thickness changes.

  • 5.
    Fernando, Harendra
    et al.
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Canning, J.
    Wosinski, Lech
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Jaskorzynska, Bozena
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Engineering UV-photosensitivity in planar lightwave circuits by plasma enhanced chemical vapour deposition2004In: Journal of Physics D: Applied Physics, ISSN 0022-3727, E-ISSN 1361-6463, Vol. 37, no 20, 2804-2809 p.Article in journal (Refereed)
    Abstract [en]

    Ion bombarding conditions were used to modify glass properties in silica-on-silicon systems during plasma enhanced chemical vapour deposition (PECVD). The induced structural modifications in the SiO2/Si system resulted in different photosensitive responses when irradiated by ArF pulsed laser operating at 193 nm wavelength. Fourier transform infrared spectroscopy was used to study the structural modifications triggered by ion bombarding conditions during film growth. The results were further confirmed by additional characterizations with regard to density (etch rate), refractive index and surface topographic measurements. The demonstrated method could be used not only to engineer UV-photosensitivity but also to control and compensate birefringence in planar lightwave devices.

  • 6.
    Jaskorzynska, Bozena
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Properties and applications of ID and 2D photonic-crystals2004In: ICTON 2004: 6TH INTERNATIONAL CONFERENCE ON TRANSPARENT OPTICAL NETWORKS, PROCEEDINGS, VOL 1 / [ed] Marciniak, M, NEW YORK: IEEE , 2004, 259-259 p.Conference paper (Refereed)
  • 7.
    Jaskorzynska, Bozena
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Qiu, Min
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Berrier, Audrey
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Dainese, Matteo
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Anand, Srinivasan
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Wosinski, Lech
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Thylén, Lars
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Zawistowski, Zygmunt J.
    Applications of wavelength dispersion in 1D and 2D photonic crystals2005In: Proceedings of SPIE - The International Society for Optical Engineering / [ed] Waclaw Urbanczyk, Bozena Jaskorzynska, Philip St. J. Russell, SPIE - International Society for Optical Engineering, 2005, 1-9 p.Conference paper (Refereed)
    Abstract [en]

    One of the most distinctive features of photonic crystals (PhCs) is their unique wavelength dispersion allowing novel device concepts for enhancement of photonic functionality and performance. Here, we present examples of our design and demonstrations utilizing dispersion properties of 1D and 2D photonic crystals. This includes the demonstration of negative refraction in 2D PhC at optical wavelengths, filters based on 1D and 2D PhC waveguides, and the design of a widely tunable filter involving 1D PhC.

  • 8.
    Jaskorzynska, Bozena
    et al.
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Sergeyev, S.
    Swillo, Marcin
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Khoptyar, D.
    Nonlinear upconversion-rate in Er-doped fibers2001In: Acta Physica Polonica. A, ISSN 0587-4246, E-ISSN 1898-794X, Vol. 99, no 1, 147-153 p.Article in journal (Refereed)
    Abstract [en]

    Energy transfer between excited rare-earth ions has been widely used for realizing upconversion lasers and also recognized as a gain limiting factor in high-concentration Er-doped amplifiers. The energy transfer leads to upconversion of the excitation which for randomly distributed (not clustered) ions is called homogeneous upconversion. It was commonly assumed that the rate of homogeneous upconversion is a linear function of the population inversion N-2. However, recently published Monte Carlo simulations predict that the homogeneous upconversion rate is a nonlinear function of N-2 and that it, moreover, depends on the pump and signals rates. In this paper we review some of our experimental results confirming those predictions. We also propose a statistical, analytical model describing the observed homogeneous upconversion behavior in Er-doped fibers.

  • 9.
    Jaskorzynska, Bozena
    et al.
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Song, Yi
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Qiu, Min
    Tradeoff between mode confinement, loss, and cross-talk, for dielectric and metal slot waveguides2009In: Photonics Letters of Poland, ISSN 2080-2242, Vol. 1, 172-174 p.Article in journal (Refereed)
    Abstract [en]

    Slot waveguides formed in high-index dielectrics or metals provide strong field enhancement in the slot region. When filled with nonlinear or lasing materials, they have the potential for highly efficient components for intensity dependent signal processing in integrated photonic circuits. In view of the increasing demand for high integration, metal slot waveguides have the great advantage of sub-diffraction mode confinement but they suffer from serious transmission loss. The total lateral field extent in their low-loss dielectric counterparts is, in turn, diffraction limited. Considering those tradeoffs, we show that at 24dB/ÎŒm cross-talk and the attenuation length of at least 5ÎŒm, gold slot waveguides can be spaced only ca 3.5 times denser than slot waveguides in silicon.

  • 10.
    Jaskorzynska, Bozena
    et al.
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Song, Yi
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Quantum Electronics and Quantum Optics, QEO.
    Zhu, Ning
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Wang, Zhechao
    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.
    Wosinski, Lech
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Dielectric and Plasmon Slot Waveguides for Photonic Integration2009In: ICTON 2009: 11th International Conference on Transparent Optical Networks: 2009 11TH INTERNATIONAL CONFERENCE ON TRANSPARENT OPTICAL NETWORKS, VOLS 1 AND 2, NEW YORK: IEEE , 2009, 653-656 p.Conference paper (Refereed)
    Abstract [en]

    Slot waveguides formed either in high-index dielectrics or in metals attract great interest because they provide sub-wavelength confinement in the slot region. While this feature is very attractive for devices relying on stimulated emission or nonlinear effects, it does not necessarily improve the integration density. The spacing between dielectric slot waveguides is still limited by diffraction. Although for metal (plasmon) waveguides the total field can be shrunk far beyond the diffraction limit, the associated increase in propagation loss will set practical limits on both the minimum waveguide width and edge-to-edge separation. Here we compare the packing densities for 3D slot waveguides in silicon and plasmon waveguides in gold with a silicon slot. As a reference we also consider silicon photonic wire. We calculate center-to-center waveguide separations (pitch) versus cross-talk level. We show that at ca 24 dB/mu m cross-talk and requiring the attenuation length of at least 5 mu m, plasmon slot waveguides can be packed ca 3.5 times denser than silicon slot waveguides, and ca 2.5 times denser than photonic wires. We also show examples of the fabricated devices.

  • 11.
    Jaskorzynska, Bozena
    et al.
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101).
    Wosinski, Lech
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101).
    Silicon-based photonic crystals and nanowires2008In: Photonic Crystals: Physics and Technology / [ed] Sibilia, C.; Benson, T.M.; Marciniak, M.; Szoplik, T., Springer, 2008, 149-169 p.Chapter in book (Refereed)
    Abstract [en]

    This Chapter highlights issues related to dense photonic integration based on silicon platform and reviews two alternatives to achieve this goal within the diffraction limit; photonic nanowires and photonic crystal waveguides. Examples of the device concepts and demonstrators, as well as the fabrication techniques for passive Si based mesostructures, are presented. Promising prospects and recent breakthroughs in heterogeneous integration of silicon with optically active materials are indicated.

  • 12.
    Jaskorzynska, Bozena
    et al.
    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.
    Wosinski, Lech
    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.
    Lourdudoss, Sebastian
    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.
    Olsson, Fredrik
    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.
    Active Si-based photonics via heterogeneous integration2008In: ICTON 2008: PROCEEDINGS OF 2008 10TH ANNIVERSARY INTERNATIONAL CONFERENCE ON TRANSPARENT OPTICAL NETWORKS, VOL 2 / [ed] Marciniak, M, NEW YORK: IEEE , 2008, 30-33 p.Conference paper (Refereed)
    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.

  • 13.
    Jaskorzynska, Bozena
    et al.
    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.
    Zawistowski, Jacek
    Polish Academy of Sciences, Poland .
    Dainese, Matteo
    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.
    Cardin, Julien
    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.
    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.
    Widely tunable directional coupler filters with 1D photonic crystal2005In: 2005 7th International Conference on Transparent Optical Networks, Vol 1, Proceedings, IEEE , 2005, 136-139 p.Conference paper (Refereed)
    Abstract [en]

    We present two concept examples for adding a wide range tunability to Si/SiO2 devices involving a photonic crystal element. They are based on a directional coupler filter of two different geometries, where one of the arms is a Bragg Reflection Waveguide (BRW) used for the bandwidth improvement. The tuning relies on changing the properties of the BRW core. As an illustration we consider the smectic A* liquid crystal as the core material and show that ca 100 nm tuning range is achievable by the core index variations of 0.006 under applying electric field of 5 V/mu m.

  • 14. Khoptyar, D.
    et al.
    Jaskorzynska, Bozena
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics.
    Experimental determination of the energy-transfer parameters for homogeneous upconversion in Er-doped silica2005In: Journal of the Optical Society of America. B, Optical physics, ISSN 0740-3224, E-ISSN 1520-8540, Vol. 22, no 10, 2091-2098 p.Article in journal (Refereed)
    Abstract [en]

    Applying a nonlinear spectroscopic technique, we accurately monitor the dynamics of the homogeneous upconversion (HUC) in Er-doped fibers. We provide the first experimental confirmation, to our knowledge, of the earlier theoretical predictions that, for low erbium concentrations, a decay of HUC-influenced excitation probability of Er ions can be well approximated by the formula describing the static HUC. By correlating the experimentally obtained HUC dynamics with the results of our analytical model in a wide range of Er concentrations, we accurately estimate energy-transfer parameters for Er-doped silica glass and experimentally assess the validity of the model.

  • 15. Khoptyar, D.
    et al.
    Jaskorzynska, Bozena
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Steady-state and switch-off behavior of upconversion in Er-doped fibers2003In: Acta Physica Polonica. A, ISSN 0587-4246, E-ISSN 1898-794X, Vol. 103, no 03-feb, 207-210 p.Article in journal (Refereed)
    Abstract [en]

    By measuring the metastable and the upconverted fluorescence in Er-doped fibers we determine rate of homogeneous upconversion as a function of the population inversion. The results confirm the prediction of our statistical model that at the same population inversion the upconversion rates under the steady-state and the switch-off conditions are different. The larger rate of the steady state upconversion is attributed to the pump enhanced, redistribution of the excitation energy.

  • 16. Khoptyar, D.
    et al.
    Sergeyev, S.
    Jaskorzynska, Bozena
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics.
    Homogeneous upconversion in Er-doped fibers under steady state excitation: analytical model and its Monte Carlo verification2005In: Journal of the Optical Society of America. B, Optical physics, ISSN 0740-3224, E-ISSN 1520-8540, Vol. 22, no 3, 582-590 p.Article in journal (Refereed)
    Abstract [en]

    We present an extension to our earlier proposed statistical model for studying migration-assisted homogeneous upconversion in erbium-doped fibers. The extension takes into account minimum proximity distance between erbium ions randomly distributed in the host material and the nonuniformity of the excitation distribution among them. We derive a transcendental equation for the population inversion and find the dependence of the upconversion rate on the population inversion and the pump power for the entire range of feasible Er concentrations. We verify the validity and accuracy of the model by means of time-resolved Monte Carlo simulations.

  • 17. Khoptyar, D.
    et al.
    Sergeyev, S.
    Jaskorzynska, Bozena
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics.
    Upconversion assisted decay of population inversion in Er-doped silica after delta-pulse excitation2005In: IEEE Journal of Quantum Electronics, ISSN 0018-9197, E-ISSN 1558-1713, Vol. 41, no 2, 205-212 p.Article in journal (Refereed)
    Abstract [en]

    We investigate homogeneous upconversion (HUC) assisted decay of the population inversion in Er-doped silica after delta-pulse excitations by means of Monte Carlo simulations. We derive an analytic expression for this decay when energy migration among Er is negligible and show that it is essentially an extension of the Forster-type donor-acceptor quenching decay for the case when donor and acceptor ions are the same species. We compare HUC during the decay to HUC while pumping CW and show that they considerably differ at the low and moderate Er concentrations. Based on Monte Carlo (MC) simulations, we construct a neuristic approximation to the HUC assisted decay, which makes our MC results readily available for the future experimental and theoretical studies and provides simple means for determination of HUC parameters by fitting to experimental data.

  • 18.
    Khoptyar, Dmitry
    et al.
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Jaskorzynska, Bozena
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Sergeyev, S.
    Analytic approximation for migration assisted upconversion in Er-doped silica after short-pulse excitation2004In: OSA Trends in Optics and Photonic, 2004, 1361-1363 p.Conference paper (Refereed)
    Abstract [en]

    We propose an analytic approximation describing the decay of the population inversion in Er-doped silica affected by the migration assisted homogeneous upconversion. We show that the results well agree with the Monte-Carlo simulations.

  • 19. Kulbickas, A.
    et al.
    Tamuliene, J.
    Rasteniene, L.
    Franckevicius, M.
    Vaisnoras, R.
    Marcos, M.
    Serrano, J. L.
    Jaskorzynska, Bozena
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics.
    Wosinski, Lech
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics.
    Optical study and structure modelling of PPI liquid crystalline dendrimer derivatives2007In: Photonics and Nanostructures-Fundamentals and Applications, ISSN 1569-4410, Vol. 5, no 4, 178-183 p.Article in journal (Refereed)
    Abstract [en]

    Optical study of two families of poly(propylene imine) (PPI) dendrimers (G = 1-5) are reported. The enlarging of the chain number (generations) of the PPI dendrimer leads to the spectra shift to IR region in solvent until 8 and 19 nm for both families, respectively. The theoretical modelling of the dendrimer structure was performed. The geometric characterization of dendrimer structure demonstrates that the preferable free space for encapsulation is periphery of the PPI dendrimer.

  • 20. Mulot, M.
    et al.
    Anand, Srinivasan
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Swillo, Marcin
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Qiu, Min
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Jaskorzynska, Bozena
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Talneau, A.
    Low-loss InP-based photonic-crystal waveguides etched with Ar/Cl-2 chemically assisted ion beam etching2003In: Journal of Vacuum Science & Technology B, ISSN 1071-1023, E-ISSN 1520-8567, Vol. 21, no 2, 900-903 p.Article in journal (Refereed)
    Abstract [en]

    We demonstrate low-loss photonic-crystal (PC) waveguides realized in InP by Ar/Cl-2 based chemically assisted ion,beam etching. The waveguides are obtained as line defects in a triangular lattice of holes etched through a three-layer InP/GaInAsP/InP heterostructure. By optimizing the etching parameters so that the physical and the chemical components are balanced we succeed in obtaining holes deeper than 2 mum even for a hole diameter as small as 220 nm. The quality of the PCs etched by two different process conditions is compared by using the shape and the position of one of the mode gaps as an assessment tool;The measured transmissions spectra indicate that the PC waveguides etched with an optimized process exhibit losses smaller than 1 dB/100 mum. This is to date the lowest loss value reported for PC waveguides in semiconductor heterostructures at optical communication wavelengths.

  • 21. Mulot, M.
    et al.
    Qiu, Min
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Swillo, Marcin
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Jaskorzynska, Bozena
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Anand, Srinivasan
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Talneau, A.
    In-plane resonant cavities with photonic crystal boundaries etched in InP-based heterostructure2003In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 83, no 6, 1095-1097 p.Article in journal (Refereed)
    Abstract [en]

    The optical properties of in-plane cavities with photonic crystal boundaries fabricated into an InP/GaInAsP/InP slab waveguide structure are presented. The investigated cavities are realized as segments of different lengths bounded by V-shaped double or single mirrors in straight photonic crystal waveguides and were designed to have resonance in the 1.55 mum wavelength range. High aspect ratio etching of the photonic crystal is achieved using Ar/Cl-2-based chemically assisted ion beam etching. The optical loss inside the photonic crystal waveguide was determined by fitting the measured transmission spectra with two-dimensional finite-difference time-domain simulations. The experimental results, combined with the simulations, indicate that major sources of loss in these cavities are radiation through the cavity mirrors and out-of-plane scattering of the third-order mode inside of the cavity. The best results were obtained for a 6.2 mum long resonant cavity with double mirrors that had an appreciably high-quality factor of 460.

  • 22.
    Qiu, Min
    et al.
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Azizi, K.
    Karlsson, Anders
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Swillo, Marcin
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Jaskorzynska, Bozena
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Numerical studies of mode gaps and coupling efficiency for line-defect waveguides in two-dimensional photonic crystals2001In: Physical Review B Condensed Matter, ISSN 0163-1829, E-ISSN 1095-3795, Vol. 6415, no 15Article in journal (Refereed)
    Abstract [en]

    Using conventional waveguides. for light coupling and collection we numerically study band structures and transmission spectra for guided modes in line-defect waveguides. obtained by removing rows of air holes in a lossless triangular-lattice two-dimensional photonic crystal. The two-dimensional finite-difference time-domain method combined with the effective index method and complemented with the coupled mode approximation is employed to analyze mode-gaps (or mini stopbands) arising from Bragg diffraction of the incident mode into the counterpropagating modes. We also show that more than 97% coupling efficiency between the ridge and the photonic crystal waveguides. is achievable by adjustment of the ridge waveguide width.

  • 23.
    Qiu, Min
    et al.
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Jaskorzynska, Bozena
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Design of a channel drop filter in a two-dimensional triangular photonic crystal2003In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 83, no 6, 1074-1076 p.Article in journal (Refereed)
    Abstract [en]

    A design of a channel drop filter in a two-dimensional photonic crystal with a triangular lattice of air holes is presented. The requirement of the accidental degeneracy of the frequency is achieved by tuning the radii of the air holes in the cavity system. In contrast to the other designs proposed, the present one does not involve either inclusion of additional materials or an extra small feature size.

  • 24.
    Qiu, Min
    et al.
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Jaskorzynska, Bozena
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Swillo, Marcin
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Benisty, H.
    Time-domain 2D modeling of slab-waveguide-based photonic-crystal devices in the presence of radiation losses2002In: Microwave and optical technology letters (Print), ISSN 0895-2477, E-ISSN 1098-2760, Vol. 34, no 5, 387-393 p.Article in journal (Refereed)
    Abstract [en]

    Devices based on two-dimensional (2D) photonic crystals (PCs) arc typically realized as 3D structures consisting of an array of holes (or rods) vertically etched through a slab waveguide. The existence of holes in a slob waveguide may induce strong radiation losses to the slab claddings. Exact modeling of devices affected by such losses requires 3D calculations. In the present Letter, with the use of the effective-index method to account for the vertical confinement and the effective losses method by the nonvanishing conductivity, the 3D modeling is reduced into 2D. It is then shown that good agreement with experiments can be obtained for slab-waveguide-based photonic crystal devices.

  • 25.
    Qiu, Min
    et al.
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Mulot, M.
    Swillo, Marcin
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Anand, Srinivasan
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Jaskorzynska, Bozena
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Karlsson, Anders
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Kamp, M.
    Forchel, A.
    Photonic crystal optical filter based on contra-directional waveguide coupling2003In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 83, no 25, 5121-5123 p.Article in journal (Refereed)
    Abstract [en]

    Wavelength-selective operation of an optical filter (add/drop) based on a contra-directional photonic crystal waveguide coupler is demonstrated. The waveguides are defined as line defects in a two-dimensional triangular photonic crystal fabricated in an InP/GaInAsP heterostructure. The device is characterized using the end-fire method for the drop functionality. The experimental data are in good agreement with the theoretical results predicted by finite-difference time-domain simulations.

  • 26.
    Qiu, Min
    et al.
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Mulot, Mikael
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Swillo, Marcin
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Srinivasan, Anand
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Jaskorzynska, Bozena
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Karlsson, Anders
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Thylén, Lars
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Optical add/drop filters using two-dimensional photonic crystals2004In: Proceedings of SPIE - The International Society for Optical Engineering, 2004, 286-295 p.Conference paper (Refereed)
    Abstract [en]

    Optical add/drop filters using two-dimensional photonic crystals (PC's) are presented for different designs. In-plane channel add/drop filter composed of two waveguides and an optical resonator system is very compact, but sensitive to the losses. While add/drop filter based on a contra-directional PC waveguide coupler is much more robust to the losses, and reasonable compactness is possible with careful designs. The possibility to utilize the PC dispersion properties to design optical filters is also discussed briefly.

  • 27.
    Qiu, Min
    et al.
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Thylén, Lars
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Swillo, Marcin
    Jaskorzynska, Bozena
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Wave propagation through a photonic crystal in a negative phase refractive-index region2003In: IEEE Journal of Selected Topics in Quantum Electronics, ISSN 1077-260X, E-ISSN 1558-4542, Vol. 9, no 1, 106-110 p.Article in journal (Refereed)
    Abstract [en]

    The wave propagation through a photonic crystal with a triangular lattice of air holes realized in the InP-InGaAsP heterostructure are studied theoretically for the transverse magnetic modes. The photonic crystal possesses a negative refractive index, and the self-focus of the beam is successfully observed. The weak side beams are observed due to high-order Bloch waves in the photonic crystal. The coupling efficiency for the outgoing waves to a waveguide is also studied.

  • 28. Sergeyev, S.
    et al.
    Khoptyar, D.
    Jaskorzynska, Bozena
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Upconversion and migration in erbium-doped silica waveguides in the continuous-wave excitation switch-off regime2002In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 65, no 23Article in journal (Refereed)
    Abstract [en]

    Based on an approach for averaging solution of rate equations over possible ensemble configurations, we derive integral equation for population inversion taking into account nonlinear homogeneous upconversion and migration in Er3+-doped silica waveguides for the case of 1480-nm CW excitation switch-off (CWES) regime. Because of pump for CWES is off, only migration tends to refill the holes in excitation distribution caused by upconversion. Thus the upconversion is weaker than that for the CW operation, except for t=0 and t-->infinity, upconversion.

  • 29. Sergeyev, S. V.
    et al.
    Jaskorzynska, Bozena
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Statistical model for energy-transfer-induced up-conversion in Er3+-doped glasses2000In: Physical Review B Condensed Matter, ISSN 0163-1829, E-ISSN 1095-3795, Vol. 62, no 23, 15628-15633 p.Article in journal (Refereed)
    Abstract [en]

    We present a statistical model for studying excitation upconversion and migration caused by energy transfer between Er3+ ions in a glass matrix. Assuming a statistically uniform distribution of ions in the matrix we propose an approach for averaging the solution of the rate equations over possible ensemble configurations. The model provides a transcendental equation for the population inversion and the up-conversion rate in the steady-state case, and an integral equation for delta -pulse excitation. Analytical expressions are given for the asymptotes at small and large population inversions, as well as at the initial time fur the dynamic case. The model explains well the experimentally observed nonlinear dependence of the up-conversion rate versus population inversion, and the enhancement of the up-conversion caused by the migration.

  • 30.
    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, 205-241 p.Chapter 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.

  • 31.
    Wosinski, Lech
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP. KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP. KTH, School of Information and Communication Technology (ICT), Centres, Kista Photonics Research Center, KPRC.
    Jaskorzynska, Bozena
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP. KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP. KTH, School of Information and Communication Technology (ICT), Centres, Kista Photonics Research Center, KPRC.
    Silicon technology for photonic crystal- and nanowire devices2008In: ICTON 2008: PROCEEDINGS OF 2008 10TH ANNIVERSARY INTERNATIONAL CONFERENCE ON TRANSPARENT OPTICAL NETWORKS, VOL 2 / [ed] Marciniak, M, NEW YORK: IEEE , 2008, 21-24 p.Conference paper (Refereed)
    Abstract [en]

    In this talk we will discuss issues related to technology for dense photonic integration based on silicon platform, and review two alternatives to achieve this goal within the diffraction limit; photonic nanowires and photonic crystal waveguides. We will also present examples of our demonstrators to illustrate the feasibility of photonic wires for device miniaturization and benefits offered by photonic crystal dispersion.

  • 32.
    Wosinski, Lech
    et al.
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Zhu, Ning
    KTH, School of Information and Communication Technology (ICT), Material Physics, Material Physics, MF.
    Jaskorzynska, Bozena
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Photonics.
    Silicon-Based Integrated Multiplexers for WDM Systems2009In: ICTON: 2009 11TH INTERNATIONAL CONFERENCE ON TRANSPARENT OPTICAL NETWORKS, NEW YORK: IEEE , 2009, 1267-1270 p.Conference paper (Refereed)
    Abstract [en]

    Wavelength Division Multiplexing systems use multiplexers and demultiplexers to increase network capacity by allowing several information channels to be placed into one fiber. Depending on the application multiplexers and demultiplexers can have wide, coarse or dense channel spacing as well as different number of channels that they process. There are many techniques available today for realization of these passive, wavelength selective components including: thin film filters, Bragg gratings, arrayed waveguide gratings and echelle gratings. The last two solutions appear to be most suitable for wafer scale mass production. Silicon-based technology additionally allows for a high level of integration and compatibility with CMOS processing. Here we discuss issues related to different solutions and fabrication technologies and compare two of them based on planar lightwave circuits. We will illustrate with designed and fabricated components for different applications.

  • 33. Zawistowski, Z. J.
    et al.
    Jaskorzynska, Bozena
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT. Polish Academy of Sciences, Poland .
    Electrically tunable filter based on directional coupler with ID photonic crystal arm infiltrated with smetic liquid crystal2004In: Proceedings of 2004 6th International Conference on Transparent Optical Networks, 2004, 127-130 p.Conference paper (Refereed)
    Abstract [en]

    We propose a concept for an electrically tunable optical filter based on a directional coupler consisting of a conventional silica glass waveguide and a ID photonic-crystal waveguide formed as a stack of alternating Si and SiO 2 layers with an electroclinic smectic A* liquid crystal as a defect layer (core). We theoretically show that with a commercially available liquid crystal BDH764E tuning ranges as large as 80 nm in the 1.55μm WDM band are possible under applying electric field of less than 5 V/μm.

  • 34. Zawistowski, Zygmunt J.
    et al.
    Jaskorzynska, Bozena
    KTH, School of Engineering Sciences (SCI), Applied Physics, Optics and Photonics, OFO.
    Modeling structures of 1D PhC for telecommunication applications2016In: PHOTONICS APPLICATIONS IN ASTRONOMY, COMMUNICATIONS, INDUSTRY, AND HIGH-ENERGY PHYSICS EXPERIMENTS 2016, SPIE - International Society for Optical Engineering, 2016, UNSP 100310ZConference paper (Refereed)
    Abstract [en]

    Effective method of modeling 1-dimensional photonic crystals structures is presented. As an illustration of the method a concept of widely tunable narrow band drop filter is described. As an active electro-optic material a liquid crystal is used. Very good parameters are obtained so the presented structure is suitable for fast packet switched wavelength division multiplexing networks (WDM).

  • 35. Zientkiewicz, Jacek K.
    et al.
    Lach, Zbigniew T.
    Grabiec, Piotr
    Driessen, Alfred
    Jaskorzynska, Bozena
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Quantum Electronics and Quantum Optics, QEO (moved to SCI 2011-07-01).
    Wosinski, Lech
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Quantum Electronics and Quantum Optics, QEO (moved to SCI 2011-07-01).
    A roadmap to a technological platform for integrating nanophotonic structures with micromechanical systems in silicon-on-insulator2005In: Integrated Optics: Theory and Applications / [ed] Pustelny T., Lambeck P.V., Gorecki C., SPIE - International Society for Optical Engineering, 2005, 59560H- p.Conference paper (Refereed)
    Abstract [en]

    On the foundation of joint experience acquired by several research centres there was defined the roadmap to the desired single technological platform for fabrication of a specific class of photonic integrated circuits, which are controlled by mechanical means. In the paper the challenges of fabrication of such photonic circuits are discussed. The main arguments in favour of the Silicon-on-Insulator materials system as the basis for the platform are presented. Options for the mechanics-to-optics arrangement, materials and processes are described and illustrated with the current achievements from the authors' labs. In the roadmap the preference is given to the vertical arrangement in which, the mechanical part is stacked above the waveguiding layer. A flexible trimming routine is designed to complement the process flow if the technologies developed cannot provide the required reproducibility.

1 - 35 of 35
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