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Ivo Montrosset - One of the best experts on this subject based on the ideXlab platform.

  • design and analysis of enhanced modulation response in integrated coupled cavities DBR Lasers using photon photon resonance
    Photonics, 2016
    Co-Authors: Paolo Bardella, Weng W Chow, Ivo Montrosset
    Abstract:

    In the last few decades, various solutions have been proposed to increase the modulation bandwidth and, consequently, the transmission bit-rate of semiconductor Lasers. In this manuscript, we discuss a design procedure for a recently proposed laser cavity realized with the monolithic integration of two distributed Bragg reflector (DBR) Lasers allowing one to extend the modulation bandwidth. Such an extension is obtained introducing in the dynamic response a photon-photon resonance (PPR) at a frequency higher than the modulation bandwidth of the corresponding single-section laser. Design guidelines will be proposed, and dynamic small and large signal simulations results, calculated using a finite difference traveling wave (FDTW) numerical simulator, will be discussed to confirm the design results. The effectiveness of the design procedure is verified in a structure with PPR frequency at 35 GHz allowing one to obtain an open eye diagram for a non-return-to-zero (NRZ) digital signal up to 80 GHz . Furthermore, the investigation of the rich dynamics of this structure shows that with proper bias conditions, it is possible to obtain also a tunable self-pulsating signal in a frequency range related to the PPR design.

  • a new design procedure for DBR Lasers exploiting the photon photon resonance to achieve extended modulation bandwidth
    IEEE Journal of Selected Topics in Quantum Electronics, 2013
    Co-Authors: Paolo Bardella, Ivo Montrosset
    Abstract:

    This paper presents a systematic investigation on the exploitation of the modulation bandwidth enhancement that can be obtained using the photon-photon resonance (PPR) effects in distributed Bragg reflector (DBR) Lasers with antireflection coating at the grating end facet. For the first time, to the best of our knowledge, a complete design procedure has been found that allows a precise positioning of the PPR frequency; such a procedure has been successfully validated both in small and large signal modulation regimes. Conditions for maximum bit rate transmission are also discussed and verified analyzing the eye diagrams obtained by numerical simulations.

  • design and simulation of DBR Lasers with extended modulation bandwidth exploiting photon photon resonance effect
    European Conference on Integrated Optics ECIO’2012, 2012
    Co-Authors: Paolo Bardella, Ivo Montrosset
    Abstract:

    In high-speed laser devices the occurrence of a pho-ton-photon resonance increases the modulation bandwidth sub-stantially. In this paper our attention is focused on the design of DBR Lasers in which this effect is exploited

  • analysis of self pulsating three section DBR Lasers
    IEEE Journal of Selected Topics in Quantum Electronics, 2005
    Co-Authors: Paolo Bardella, Ivo Montrosset
    Abstract:

    The characteristics of a three-section distributed Bragg reflector laser showing self-pulsation have been analyzed using a large signal time-domain traveling-wave simulator. The device dynamic properties have been investigated in all their complexity and analyzed as functions of the linewidth enhancement factor and of the injected current in the active and in the phase control sections. The simulation results have clearly shown the fundamental role of four wave mixing on the laser characteristics (output power, spectrum, etc.) and have been quantitatively correlated with the few available theoretical and experimental results. The considered self-pulsation operation frequencies around 40 GHz are of interest for practical applications.

  • Novel interleaved sampled grating mirrors for widely tunable DBR Lasers
    IEE Proceedings - Optoelectronics, 2001
    Co-Authors: Mariangela Gioannini, Ivo Montrosset
    Abstract:

    Novel sampled grating mirrors with interleaved gratings (ISGs) are proposed for the realisation of widely tunable DBR Lasers based on the Vernier principle. The ISG design parameters used to control the spacing of the peaks and the shape of the maximum reflectivity envelope are presented in a design example of a widely tunable DBR laser. The simulated performances of ISG-DBR are compared with those of a sampled grating-DBR laser with the same length and the same maximum reflectivity for each mirror. The advantages gained from interleaving are discussed, paying particular attention to the static characteristics in the tuning range. It is shown that ISGs limit the threshold current variations in the coarse tuning operation mode because of the flatter envelope of the reflectivity maxima and can be useful to reduce the output power variations in the continuous tuning operation mode.

J J Coleman - One of the best experts on this subject based on the ideXlab platform.

  • narrow linewidth surface etched DBR Lasers fundamental design aspects and applications
    IEEE Journal of Selected Topics in Quantum Electronics, 2013
    Co-Authors: Kirk Price, J W Zimmerman, U Reddy, N L Dias, J J Coleman
    Abstract:

    Surface-etched distributed Bragg reflector (SE-DBR) semiconductor Lasers show potential for use in a variety of communications and spectroscopy applications requiring compact, single-mode, narrow linewidth, and tunable laser sources. This approach eliminates contamination issues associated with forming gratings by regrowth in Al-containing structures by using a single growth step and etching the grating after the entire epitaxy is grown. This paper reviews progress in the development of SE-DBR Lasers using InGaAs-GaAs-AlGaAs and GaAs-AlGaAs separate confinement heterostructure. Fabrication techniques, design optimization studies, and device performance characteristics are overviewed. Applications of SE-DBRs toward multiwavelength arrays, THz generation via optical heterodyning, and alkali spectroscopy are discussed.

  • dual wavelength asymmetric cladding ingaas gaas ridge waveguide distributed bragg reflector Lasers
    IEEE Photonics Technology Letters, 1999
    Co-Authors: J S Hughes, A M Jones, R B Swint, T S Yeoh, A E Huber, J J Coleman
    Abstract:

    The design and operation of dual-wavelength InGaAs-GaAs asymmetric cladding ridge waveguide distributed Bragg reflector (DBR) Lasers are reported. DBR Lasers with mode pair separations of 4.1, 8.4, and 16.9 nm exhibit stable, simultaneous, dual-wavelength operation in current ranges of 40-52 mA, 32-42 mA, and 28-35 mA, respectively. Within the stated current ranges, all lasing modes exhibit at least 20-dB sidemode suppression, and approximately 30-dB sidemode suppression under optimum operating conditions.

  • InGaAsP-InP ridge-waveguide DBR Lasers with first-order surface gratings fabricated using CAIBE
    IEEE Photonics Technology Letters, 1997
    Co-Authors: R M Lammert, C.T. Youtsey, Ilesanmi Adesida, J S Hughes, A M Jones, J J Coleman
    Abstract:

    The design and operation of InGaAsP-InP ridge-waveguide (RW) distributed Bragg reflector (DBR) multiple quantum-well Lasers with first-order surface gratings are presented. The RW DBR Lasers are fabricated using only a single growth step without growth on a corrugated surface. Uncoated devices with grating etch depths of 0.6 and 0.5-μm exhibit pulsed threshold currents of 32 and 43 mA with slope efficiencies of 0.34 and 0.24 W/A, respectively. The device with a grating etch depth of 0.5-μm operates on a single longitudinal mode with about 40 dB side-mode suppression. All these results are from devices with Bragg condition wavelengths which are red-shifted from the peak spontaneous emission wavelength by over 400 /spl Aring/.

Yuzo Yoshikuni - One of the best experts on this subject based on the ideXlab platform.

  • Mode stabilization method for superstructure-grating DBR Lasers
    Journal of Lightwave Technology, 1998
    Co-Authors: Hiroyuki Ishii, Fumiyoshi Kano, Yuzo Yoshikuni, Hiroshi Yasaka
    Abstract:

    A wavelength stabilization method for widely tunable superstructure-grating (SSG) distributed Bragg reflector (DBR) laser is described. The output characteristics under tuning are studied theoretically and experimentally. It is found that peak reflectivity states, in which the lasing mode is just aligned with the reflection peaks of both DBR's, are obtained at saddle points in the output characteristics while changing the two SSG-DBR currents. Based on these results, a method for the Bragg frequency control of the two SSG-DBRs is proposed. The feedback control circuit keeps the lasing mode at a peak reflectivity state, and it suppresses mode hopping. Additionally, the oscillation mode is locked to arbitrary reference wavelengths of an optical filter. Stabilization at 200 GHz (1.6 nm)-spaced 16 wavelengths was achieved within the wide tuning range of the SSG-DBR laser. Control was maintained under a laser temperature variation of /spl plusmn/5/spl deg/C as a result of the Bragg frequency control of the two DBR's.

  • Quasicontinuous wavelength tuning in super-structure-grating (SSG) DBR Lasers
    IEEE Journal of Quantum Electronics, 1996
    Co-Authors: Hiroyuki Ishii, Fumiyoshi Kano, Yuichi Tohmori, Y. Kondo, H. Tanobe, Yuzo Yoshikuni
    Abstract:

    The paper describes the design of a super-structure-grating distributed Bragg reflector (SSG-DBR) laser for broad quasicontinuous wavelength tuning with stable single-mode operation. The phase distributions and the effective coupling coefficients of SSG's are optimized to obtain both broad tuning range and high mode selectivity. A computer-aided simulation of wavelength tuning, where the effects of the waveguide loss increase and inhomogeneous gain spectrum are included, provides an optimum cavity structure and indicates the possibility of more than 70 mm quasicontinuous tuning in a 1.55 /spl mu/m InGaAsP-InP SSG-DBR laser. Experimental results for 34 nm quasicontinuous tuning with a properly designed device are also presented.

  • broad range wavelength tunable superstructure grating ssg DBR Lasers
    IEEE Journal of Quantum Electronics, 1993
    Co-Authors: Yuichi Tohmori, Fumiyoshi Kano, Yuzo Yoshikuni, Y. Kondo, Hiroyuki Ishii, Toshiaki Tamamura, M Yamamoto
    Abstract:

    A broad tuning range is demonstrated in tunable DBR Lasers with a novel superstructure grating (SSG). These SSG reflectors were fabricated by electron-beam lithography, and grating performance was evaluated by measuring the transmittance characteristics of a ridge-type SSG reflector. Incorporating this SSG reflector into distributed-Bragg-reflector (DBR) laser results in Lasers that can be tuned over a wide wavelength range by using coarse and fine tuning mechanisms. Wavelength-tunable SSG DBR Lasers were fabricated and operated under low-threshold CW conditions. Wavelength tuning ranges of 50 and 100 nm were designed and experimentally measured to be 50 and 83 nm, respectively, with single-mode operation. >

  • multiple phase shift super structure grating DBR Lasers for broad wavelength tuning
    IEEE Photonics Technology Letters, 1993
    Co-Authors: H Ishii, Yuichi Tohmori, Yuzo Yoshikuni, Toshiaki Tamamura, Y. Kondo
    Abstract:

    Broad range wavelength tuning in distributed Bragg reflector (DBR) Lasers using a super structure grating with multiple phase shifts is discussed. Experimental results indicate that the laser achieves a maximum tuning range of 105 nm with stable single-mode continuous wave (CW) operation. >

  • broad range wavelength tuning in DBR Lasers with super structure grating ssg
    IEEE Photonics Technology Letters, 1993
    Co-Authors: Yuichi Tohmori, Yuzo Yoshikuni, Y. Kondo, Toshiaki Tamamura, H Ishii, M Yamamoto
    Abstract:

    Broad-range wavelength tuning is demonstrated in tunable distributed Bragg reflector (DBR) Lasers with the super structure grating (SSG) proposed. The SSG is fabricated by electron beam exposure lithography. The grating performance is measured by transmittance characteristics of the SSG reflector. A maximum tuning range of 63 nm is obtained under the CW condition while keeping a single longitudinal mode. In a 50-nm tuning range, the threshold current variation is as low as 5.0-9.5 mA. >

Yuichi Tohmori - One of the best experts on this subject based on the ideXlab platform.

  • lasing wavelength changes due to degradation in buried heterostructure distributed bragg reflector Lasers
    Journal of Lightwave Technology, 1999
    Co-Authors: Hiroyasu Mawatari, Yuichi Tohmori, Mitsuo Fukuda, F Kano, Y Yoshikuni, H Toba
    Abstract:

    Changes in the wavelength and lamp characteristics due to the degradation of distributed Bragg reflector (DBR) Lasers are investigated and the Lasers are confirmed to be reliable enough for application as the light sources in WDM systems. The change in wavelength characteristics is due to degradation of the DBR or phase control region and the change in lamp characteristics is due to the degradation of active region. These changes in the characteristics are caused by diminished recombination carrier lifetime. The wavelength stability is strongly correlated with the injected current density. The lamp characteristics is confirmed to be almost as stable as in conventional Fabry-Perot Lasers. The applicability of DBR Lasers as the light source for wavelength division multiplexing (WDM) systems is demonstrated for actual-use conditions.

  • Quasicontinuous wavelength tuning in super-structure-grating (SSG) DBR Lasers
    IEEE Journal of Quantum Electronics, 1996
    Co-Authors: Hiroyuki Ishii, Fumiyoshi Kano, Yuichi Tohmori, Y. Kondo, H. Tanobe, Yuzo Yoshikuni
    Abstract:

    The paper describes the design of a super-structure-grating distributed Bragg reflector (SSG-DBR) laser for broad quasicontinuous wavelength tuning with stable single-mode operation. The phase distributions and the effective coupling coefficients of SSG's are optimized to obtain both broad tuning range and high mode selectivity. A computer-aided simulation of wavelength tuning, where the effects of the waveguide loss increase and inhomogeneous gain spectrum are included, provides an optimum cavity structure and indicates the possibility of more than 70 mm quasicontinuous tuning in a 1.55 /spl mu/m InGaAsP-InP SSG-DBR laser. Experimental results for 34 nm quasicontinuous tuning with a properly designed device are also presented.

  • broad range wavelength tunable superstructure grating ssg DBR Lasers
    IEEE Journal of Quantum Electronics, 1993
    Co-Authors: Yuichi Tohmori, Fumiyoshi Kano, Yuzo Yoshikuni, Y. Kondo, Hiroyuki Ishii, Toshiaki Tamamura, M Yamamoto
    Abstract:

    A broad tuning range is demonstrated in tunable DBR Lasers with a novel superstructure grating (SSG). These SSG reflectors were fabricated by electron-beam lithography, and grating performance was evaluated by measuring the transmittance characteristics of a ridge-type SSG reflector. Incorporating this SSG reflector into distributed-Bragg-reflector (DBR) laser results in Lasers that can be tuned over a wide wavelength range by using coarse and fine tuning mechanisms. Wavelength-tunable SSG DBR Lasers were fabricated and operated under low-threshold CW conditions. Wavelength tuning ranges of 50 and 100 nm were designed and experimentally measured to be 50 and 83 nm, respectively, with single-mode operation. >

  • multiple phase shift super structure grating DBR Lasers for broad wavelength tuning
    IEEE Photonics Technology Letters, 1993
    Co-Authors: H Ishii, Yuichi Tohmori, Yuzo Yoshikuni, Toshiaki Tamamura, Y. Kondo
    Abstract:

    Broad range wavelength tuning in distributed Bragg reflector (DBR) Lasers using a super structure grating with multiple phase shifts is discussed. Experimental results indicate that the laser achieves a maximum tuning range of 105 nm with stable single-mode continuous wave (CW) operation. >

  • super structure grating ssg for broadly tunable DBR Lasers
    IEEE Photonics Technology Letters, 1993
    Co-Authors: H Ishii, Yuichi Tohmori, T Tamamura, Y Yoshikuni
    Abstract:

    The reflection characteristics of super-structure-grating (SSG) reflectors are demonstrated theoretically and experimentally. The periodic multireflection peaks with high reflectivities of 68 approximately 98% are theoretically shown in the reflection spectrum. The experimental characteristics of a ridge-type SSG reflector are in good agreement with the theoretical design. >

Larry A. Coldren - One of the best experts on this subject based on the ideXlab platform.

  • direct intensity modulation in sampled grating DBR Lasers
    IEEE Photonics Technology Letters, 2002
    Co-Authors: M L Majewski, Larry A. Coldren, Y A Akulova, J S Barton, M C Larson
    Abstract:

    In this letter, we present new experimental results obtained for direct intensity modulation of widely tunable sampled-grating distributed Bragg-reflector (SGDBR) Lasers. These results are of significance to SGDBR applications in wavelength-division-multiplexing systems. The devices described operate in the C-band (wavelength range 1525-1565 nm). A 6-GHz small-signal modulation bandwidth and >10-dB signal extinction ratio under large-signal operation were obtained. We have also recorded an undistorted eye pattern for a nonreturn-to-zero random signal 2/sup 31/-1 word length at 2.5-Gb/s bit rate during transmission over 75-km of standard single-mode fiber.

  • Tunable sampled-grating DBR Lasers using quantum-well intermixing
    IEEE Photonics Technology Letters, 2002
    Co-Authors: E.j. Skogen, S P Denbaars, J S Barton, Larry A. Coldren
    Abstract:

    Widely tunable Lasers are key components for wavelength division multiplexing fiber optic networks. They reduce cost in sparing, enable dynamic networking applications, and present opportunities for future monolithically integrated wavelength division multiplexing components. The sampled-grating distributed Bragg reflector (SGDBR) laser is ideal for these purposes. The authors present a centered quantum-well SGDBR laser which uses quantum-well intermixing in order to improve device characteristics over previous designs. The mode overlap is improved by 50% over the offset quantum-well design, improving the modal gain. Current injection tuning in the intermixed material is demonstrated for the first time; the maximum modal group index change was measured to be 1%.

  • design of sampled grating DBR Lasers with integrated semiconductor optical amplifiers
    IEEE Photonics Technology Letters, 2000
    Co-Authors: B Mason, Gregory A. Fish, Larry A. Coldren, J S Barton, S P Denbaars
    Abstract:

    High output powers and wide range quasicontinuous tuning have been achieved in a sampled-grating distributed Bragg reflector laser with an integrated semiconductor-optical-amplifier. Using an amplifier with a curved passive output waveguide to suppress back reflection, we have achieved a quasicontinuous tuning range of over 50 nm and peak output powers greater than +8 dBm. Optimizing the device structure and the sampled-grating mirror design has enabled tuning ranges of up to 72 nm in devices without amplifiers.

  • directly modulated sampled grating DBR Lasers for long haul wdm communication systems
    IEEE Photonics Technology Letters, 1997
    Co-Authors: B Mason, M.e. Heimbuch, San-liang Lee, Larry A. Coldren
    Abstract:

    The limitations on high-speed data transmission, using widely tunable sampled-grating distributed Bragg reflector (SGDBR) Lasers, are investigated. We demonstrate 1.244-Gb/s data transmission over a wavelength range of 45 nm using a single directly modulated tunable SGDBR laser diode. Data transmission was evaluated on four separate wavelength channels each spaced 15 nm apart. Less than 0.6 dB of dispersion penalty was measured on all four channels for transmission over 50 km of standard single-mode optical fiber.

  • Dynamic responses of widely tunable sampled grating DBR Lasers
    IEEE Photonics Technology Letters, 1996
    Co-Authors: San-liang Lee, Larry A. Coldren, D. Tauber, V. Jayaraman, M.e. Heimbuch, J.e. Bowers
    Abstract:

    The modulation bandwidth, dynamic mode suppression ratio, and wavelength chirp of directly modulated sampled grating DBR Lasers have been measured. Although the tuning range can be up to an order of magnitude larger than in simple DBR Lasers, the chirp is about the same or better over a wide range of operation parameters. The modulation bandwidth was in excess of 4 GHz and the dynamic MSR remained larger than 40 dB as long as the current did not swing below threshold. The linewidth enhancement factor was extracted from the measured chirp parameters and ranged from three to eight for different lasing wavelengths of the tunable Lasers. The dispersion of the linewidth enhancement factor is consistent with published theoretical predictions.