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Frederic Grillot - One of the best experts on this subject based on the ideXlab platform.

  • influence of the polarization anisotropy on the Linewidth Enhancement Factor and reflection sensitivity of 1 55 μm inp based inas quantum dash lasers
    Applied Physics Letters, 2019
    Co-Authors: Bozhang Dong, Heming Huang, Frederic Grillot, Jianan Duan, Daehwan Jung, John E Bowers, Chen Shang, A B Sawadogo
    Abstract:

    This work investigates the effect of the polarization anisotropy on the Linewidth Enhancement Factor and the reflection sensitivity of InAs/InP quantum dash semiconductor lasers. The results show that the small Linewidth Enhancement Factor and high stability against external optical feedback are obtained for nanostructures oriented perpendicular to the cavity axis as opposed to those oriented parallel to the cavity axis. Effective simulations on the critical feedback level of these two lasers are also in agreement with experimental results. Such anisotropy is attributed to the polarization dependence of the transition matrix element in these quantum nanostructures.This work investigates the effect of the polarization anisotropy on the Linewidth Enhancement Factor and the reflection sensitivity of InAs/InP quantum dash semiconductor lasers. The results show that the small Linewidth Enhancement Factor and high stability against external optical feedback are obtained for nanostructures oriented perpendicular to the cavity axis as opposed to those oriented parallel to the cavity axis. Effective simulations on the critical feedback level of these two lasers are also in agreement with experimental results. Such anisotropy is attributed to the polarization dependence of the transition matrix element in these quantum nanostructures.

  • Low Linewidth Enhancement Factor and high optical feedback resistance of p-doped silicon based quantum dot lasers
    2018
    Co-Authors: Jianan Duan, Daehwan Jung, Justin Norman, H. Huang, J. Bowers, Frederic Grillot
    Abstract:

    This work shows that p-doped quantum dot lasers grown on silicon exhibit a low Linewidth Enhancement Factor and hence a high resistance against optical feedback which are promising for isolator-free transmissions in photonic integrated circuits.

  • semiconductor quantum dot lasers epitaxially grown on silicon with low Linewidth Enhancement Factor
    Applied Physics Letters, 2018
    Co-Authors: Jianan Duan, Heming Huang, Frederic Grillot, Daehwan Jung, Zeyu Zhang, Justin Norman, John E Bowers
    Abstract:

    This work reports on the ultra-low Linewidth Enhancement Factor (αH-Factor) of semiconductor quantum dot lasers epitaxially grown on silicon. Owing to the low density of threading dislocations and resultant high gain, an αH value of 0.13 that is rather independent of the temperature range (288 K–308 K) is measured. Above the laser threshold, the Linewidth Enhancement Factor does not increase extensively with the bias current which is very promising for the realization of future integrated circuits including high performance laser sources.This work reports on the ultra-low Linewidth Enhancement Factor (αH-Factor) of semiconductor quantum dot lasers epitaxially grown on silicon. Owing to the low density of threading dislocations and resultant high gain, an αH value of 0.13 that is rather independent of the temperature range (288 K–308 K) is measured. Above the laser threshold, the Linewidth Enhancement Factor does not increase extensively with the bias current which is very promising for the realization of future integrated circuits including high performance laser sources.

  • semiconductor quantum dot lasers epitaxially grown on silicon with low Linewidth Enhancement Factor
    Applied Physics Letters, 2018
    Co-Authors: Jianan Duan, Heming Huang, Frederic Grillot, Daehwan Jung, Zeyu Zhang, Justin Norman, John E Bowers
    Abstract:

    This work reports on the ultra-low Linewidth Enhancement Factor (αH-Factor) of semiconductor quantum dot lasers epitaxially grown on silicon. Owing to the low density of threading dislocations and resultant high gain, an αH value of 0.13 that is rather independent of the temperature range (288 K–308 K) is measured. Above the laser threshold, the Linewidth Enhancement Factor does not increase extensively with the bias current which is very promising for the realization of future integrated circuits including high performance laser sources.

  • Linewidth broadening Factor and gain compression in quantum cascade lasers
    Proceedings of SPIE, 2016
    Co-Authors: Louise Jumpertz, Frederic Grillot, Florian Michel, Robert Pawlus, W Elsasser, Mathieu Carras, Kevin Schires
    Abstract:

    In addition to the phase uctuation induced by spontaneous emission, instantaneous carrier variations in semiconductor lasers generate coupling between optical gain and refractive index. This coupling between phase and amplitude of the electric field in the optical cavity is driven by the Linewidth Enhancement Factor, which is responsible for the optical Linewidth broadening, occurrence of nonlinearities or gain asymmetry, due to the curvature difierence between the conduction and valence bands. This key parameter typically takes values between 2 and 6 in interband lasers with quantum well or quantum dot active media. In quantum cascade lasers, since the lasing transition occurs between two subbands of the conduction band that have therefore similar curvatures, the Linewidth Enhancement Factor was expected to be naught. However sub-threshold Linewidth Enhancement Factor was measured taking values from -0.5 to 0.5 and the above-threshold Linewidth Enhancement Factor at room temperature was found between 0.2 and 2.4. In this work, the Linewidth Enhancement Factor of a mid-infrared quantum cascade laser emitting around 5.6 μm is measured using either the wavelength shift under optical feedback or self-mixing interferometry, resulting in values ranging from 0.8 to 3. Furthermore, a strong increase of the Linewidth Enhancement Factor with the pump current was observed, that can be explained by a relatively large gain compression in such structures, of the order of 5 × 10-15 cm3.

John E Bowers - One of the best experts on this subject based on the ideXlab platform.

  • on quantum dot lasing at gain peak with Linewidth Enhancement Factor α h 0
    APL Photonics (Web), 2020
    Co-Authors: Weng W Chow, Zeyu Zhang, Justin Norman, Songtao Liu, John E Bowers
    Abstract:

    This paper describes an investigation of the Linewidth Enhancement Factor αH in a semiconductor quantum-dot laser. Results are presented for active region parameters and laser configurations important for minimizing αH. In particular, the feasibility of lasing at the gain peak with αH = 0 is explored. The study uses a many-body theory with dephasing effects from carrier scattering treated at the level of quantum-kinetic equations. InAs quantum-dot lasers with different p-modulation doping densities are fabricated and measured to verify the calculated criteria on laser cavity design and epitaxial growth conditions.This paper describes an investigation of the Linewidth Enhancement Factor αH in a semiconductor quantum-dot laser. Results are presented for active region parameters and laser configurations important for minimizing αH. In particular, the feasibility of lasing at the gain peak with αH = 0 is explored. The study uses a many-body theory with dephasing effects from carrier scattering treated at the level of quantum-kinetic equations. InAs quantum-dot lasers with different p-modulation doping densities are fabricated and measured to verify the calculated criteria on laser cavity design and epitaxial growth conditions.

  • influence of the polarization anisotropy on the Linewidth Enhancement Factor and reflection sensitivity of 1 55 μm inp based inas quantum dash lasers
    Applied Physics Letters, 2019
    Co-Authors: Bozhang Dong, Heming Huang, Frederic Grillot, Jianan Duan, Daehwan Jung, John E Bowers, Chen Shang, A B Sawadogo
    Abstract:

    This work investigates the effect of the polarization anisotropy on the Linewidth Enhancement Factor and the reflection sensitivity of InAs/InP quantum dash semiconductor lasers. The results show that the small Linewidth Enhancement Factor and high stability against external optical feedback are obtained for nanostructures oriented perpendicular to the cavity axis as opposed to those oriented parallel to the cavity axis. Effective simulations on the critical feedback level of these two lasers are also in agreement with experimental results. Such anisotropy is attributed to the polarization dependence of the transition matrix element in these quantum nanostructures.This work investigates the effect of the polarization anisotropy on the Linewidth Enhancement Factor and the reflection sensitivity of InAs/InP quantum dash semiconductor lasers. The results show that the small Linewidth Enhancement Factor and high stability against external optical feedback are obtained for nanostructures oriented perpendicular to the cavity axis as opposed to those oriented parallel to the cavity axis. Effective simulations on the critical feedback level of these two lasers are also in agreement with experimental results. Such anisotropy is attributed to the polarization dependence of the transition matrix element in these quantum nanostructures.

  • Linewidth Enhancement Factor in inas gaas quantum dot lasers and its implication in isolator free and narrow Linewidth applications
    IEEE Journal of Selected Topics in Quantum Electronics, 2019
    Co-Authors: Zeyu Zhang, Daehwan Jung, Justin Norman, Weng W Chow, John E Bowers
    Abstract:

    The Linewidth Enhancement Factor ( $\alpha _\mathrm{H}$ ) is an important parameter for semiconductor lasers. In this paper, we investigate, both theoretically and experimentally, the key parameters that affect $\alpha _\mathrm{H}$ of InAs/GaAs quantum dot lasers. Both dot uniformity and doping density are found to be critical in achieving small $\alpha _\mathrm{H}$ in quantum dot lasers. The prospects for quantum dot lasers in isolator-free and narrow Linewidth applications are also discussed.

  • continuous tuning of gain peak Linewidth Enhancement Factor from negative to positive with p doping in inas qd laser on si
    International Semiconductor Laser Conference, 2018
    Co-Authors: Zeyu Zhang, Daehwan Jung, Justin Norman, Weng W Chow, Pari Patel, John E Bowers
    Abstract:

    We investigate the Linewidth Enhancement Factor of 1.3 μm quantum dot lasers epitaxially grown on silicon. Both the calculation and experiment show small (<1) Linewidth Enhancement Factor at gain peak due to high dot uniformity. By varying the modulation p doping level, the Linewidth Enhancement Factor at threshold can be continuously changed across zero from negative to positive.

  • semiconductor quantum dot lasers epitaxially grown on silicon with low Linewidth Enhancement Factor
    Applied Physics Letters, 2018
    Co-Authors: Jianan Duan, Heming Huang, Frederic Grillot, Daehwan Jung, Zeyu Zhang, Justin Norman, John E Bowers
    Abstract:

    This work reports on the ultra-low Linewidth Enhancement Factor (αH-Factor) of semiconductor quantum dot lasers epitaxially grown on silicon. Owing to the low density of threading dislocations and resultant high gain, an αH value of 0.13 that is rather independent of the temperature range (288 K–308 K) is measured. Above the laser threshold, the Linewidth Enhancement Factor does not increase extensively with the bias current which is very promising for the realization of future integrated circuits including high performance laser sources.This work reports on the ultra-low Linewidth Enhancement Factor (αH-Factor) of semiconductor quantum dot lasers epitaxially grown on silicon. Owing to the low density of threading dislocations and resultant high gain, an αH value of 0.13 that is rather independent of the temperature range (288 K–308 K) is measured. Above the laser threshold, the Linewidth Enhancement Factor does not increase extensively with the bias current which is very promising for the realization of future integrated circuits including high performance laser sources.

L F Lester - One of the best experts on this subject based on the ideXlab platform.

  • strong optical injection and the differential gain in a quantum dash laser
    Optics Express, 2014
    Co-Authors: L F Lester, Frederic Grillot, N A Naderi, Ravi Raghunathan, Vassilios Kovanis
    Abstract:

    By optically injecting a quantum dash laser and simultaneously producing a significant lowering of the device threshold, a large Enhancement in the differential gain is realized. This effect is observed by way of a dramatic reduction in the Linewidth Enhancement Factor and a large increase in the 3-dB modulation bandwidth, especially as the injection wavelength is blue-shifted. Compared to its free-running value, a 50X improvement in the laser’s differential gain is found.

  • gain compression and above threshold Linewidth Enhancement Factor in 1 3 mu hbox m inas gaas quantum dot lasers
    IEEE Journal of Quantum Electronics, 2008
    Co-Authors: Frederic Grillot, Béatrice Dagens, J.-g. Provost, L F Lester
    Abstract:

    Quantum-dot (QD) lasers exhibit many useful properties such as low threshold current, temperature and feedback insensitivity, chirpless behavior, and low Linewidth Enhancement Factor (alphaH-Factor). Although many breakthroughs have been demonstrated, the maximum modulation bandwidth remains limited in QD devices, and a strong damping of the modulation response is usually observed pointing out the role of gain compression. This paper investigates the influence of the gain compression in a 1.3-mum InAs-GaAs QD laser and its consequences on the above-threshold alphaH-Factor. A model is used to explain the dependence of the alphaH-Factor with the injected current and is compared with AM/FM experiments. Finally, it is shown that the higher the maximum gain, the lower the effects of gain compression and the lower the alphaH-Factor. This analysis can be useful for designing chirpless QD lasers with improved modulation bandwidth as well as for isolator-free transmission under direct modulation.

  • gain compression coefficient and above threshold Linewidth Enhancement Factor in inas gaas quantum dfb lasers
    Physics and simulation of optoelectronic devices. Conference, 2005
    Co-Authors: L Zhang, A L Gray, R H Wang, P M Varangis, L F Lester
    Abstract:

    We measure, for the first time, the gain compression coefficient and above-threshold Linewidth Enhancement Factor (alpha parameter) in quantum dot (QD) distributed feedback lasers (DFB) by time-resolved-chirp (TRC) characterization. The alpha parameter is measured to be 2.6 at threshold and increases to 8 when the output power of the QD DFB is increased to 3 mW. The dependence of the above-threshold alpha parameter on the optical power is found to be stronger than the optical gain compression effect alone can predict. The inhomogeneous gain broadening, gain saturation at the ground states and carrier filling in the excited states in QDs are proposed to explain the results.

  • orientation dependence of the optical properties in inas quantum dash lasers on inp
    Applied Physics Letters, 2002
    Co-Authors: A A Ukhanov, A Stintz, L F Lester, R H Wang, Thomas J Rotter, P G Eliseev, K J Malloy
    Abstract:

    The anisotropy of the modal gain and the Linewidth Enhancement Factor was experimentally measured in InAs/AlGaInAs/InP semiconductor lasers with an active region composed of quantum confined structures in the form of short wires called quantum dashes. This anisotropy is due to the polarization dependence of the transition matrix element in these quantum nanostructures. The spectral dependence of the gain and Linewidth Enhancement Factor was investigated in a wavelength range from 1540 to 1640 nm at subthreshold current densities. The largest gain and the smallest Linewidth Enhancement Factor were obtained when the quantum dashes were oriented perpendicular to the axis of the laser cavity.

  • gain and Linewidth Enhancement Factor in inas quantum dot laser diodes
    IEEE Photonics Technology Letters, 1999
    Co-Authors: T C Newell, A Stintz, K J Malloy, D J Bossert, B Fuchs, L F Lester
    Abstract:

    Amplified spontaneous emission measurements are investigated below threshold in InAs quantum-dot lasers emitting at 1.22 /spl mu/m. The dot layer of the laser was grown in a strained quantum well (QW) on a GaAs substrate. Ground state gain is determined from cavity mode Fabry-Perot modulation. As the injection current increases, the gain rises super-linearly while changes in the index of refraction decrease. Below the onset of gain saturation, the Linewidth Enhancement Factor is as small as 0.1, which is significantly lower than that reported for QW lasers.

Daehwan Jung - One of the best experts on this subject based on the ideXlab platform.

  • influence of the polarization anisotropy on the Linewidth Enhancement Factor and reflection sensitivity of 1 55 μm inp based inas quantum dash lasers
    Applied Physics Letters, 2019
    Co-Authors: Bozhang Dong, Heming Huang, Frederic Grillot, Jianan Duan, Daehwan Jung, John E Bowers, Chen Shang, A B Sawadogo
    Abstract:

    This work investigates the effect of the polarization anisotropy on the Linewidth Enhancement Factor and the reflection sensitivity of InAs/InP quantum dash semiconductor lasers. The results show that the small Linewidth Enhancement Factor and high stability against external optical feedback are obtained for nanostructures oriented perpendicular to the cavity axis as opposed to those oriented parallel to the cavity axis. Effective simulations on the critical feedback level of these two lasers are also in agreement with experimental results. Such anisotropy is attributed to the polarization dependence of the transition matrix element in these quantum nanostructures.This work investigates the effect of the polarization anisotropy on the Linewidth Enhancement Factor and the reflection sensitivity of InAs/InP quantum dash semiconductor lasers. The results show that the small Linewidth Enhancement Factor and high stability against external optical feedback are obtained for nanostructures oriented perpendicular to the cavity axis as opposed to those oriented parallel to the cavity axis. Effective simulations on the critical feedback level of these two lasers are also in agreement with experimental results. Such anisotropy is attributed to the polarization dependence of the transition matrix element in these quantum nanostructures.

  • Linewidth Enhancement Factor in inas gaas quantum dot lasers and its implication in isolator free and narrow Linewidth applications
    IEEE Journal of Selected Topics in Quantum Electronics, 2019
    Co-Authors: Zeyu Zhang, Daehwan Jung, Justin Norman, Weng W Chow, John E Bowers
    Abstract:

    The Linewidth Enhancement Factor ( $\alpha _\mathrm{H}$ ) is an important parameter for semiconductor lasers. In this paper, we investigate, both theoretically and experimentally, the key parameters that affect $\alpha _\mathrm{H}$ of InAs/GaAs quantum dot lasers. Both dot uniformity and doping density are found to be critical in achieving small $\alpha _\mathrm{H}$ in quantum dot lasers. The prospects for quantum dot lasers in isolator-free and narrow Linewidth applications are also discussed.

  • Low Linewidth Enhancement Factor and high optical feedback resistance of p-doped silicon based quantum dot lasers
    2018
    Co-Authors: Jianan Duan, Daehwan Jung, Justin Norman, H. Huang, J. Bowers, Frederic Grillot
    Abstract:

    This work shows that p-doped quantum dot lasers grown on silicon exhibit a low Linewidth Enhancement Factor and hence a high resistance against optical feedback which are promising for isolator-free transmissions in photonic integrated circuits.

  • continuous tuning of gain peak Linewidth Enhancement Factor from negative to positive with p doping in inas qd laser on si
    International Semiconductor Laser Conference, 2018
    Co-Authors: Zeyu Zhang, Daehwan Jung, Justin Norman, Weng W Chow, Pari Patel, John E Bowers
    Abstract:

    We investigate the Linewidth Enhancement Factor of 1.3 μm quantum dot lasers epitaxially grown on silicon. Both the calculation and experiment show small (<1) Linewidth Enhancement Factor at gain peak due to high dot uniformity. By varying the modulation p doping level, the Linewidth Enhancement Factor at threshold can be continuously changed across zero from negative to positive.

  • semiconductor quantum dot lasers epitaxially grown on silicon with low Linewidth Enhancement Factor
    Applied Physics Letters, 2018
    Co-Authors: Jianan Duan, Heming Huang, Frederic Grillot, Daehwan Jung, Zeyu Zhang, Justin Norman, John E Bowers
    Abstract:

    This work reports on the ultra-low Linewidth Enhancement Factor (αH-Factor) of semiconductor quantum dot lasers epitaxially grown on silicon. Owing to the low density of threading dislocations and resultant high gain, an αH value of 0.13 that is rather independent of the temperature range (288 K–308 K) is measured. Above the laser threshold, the Linewidth Enhancement Factor does not increase extensively with the bias current which is very promising for the realization of future integrated circuits including high performance laser sources.This work reports on the ultra-low Linewidth Enhancement Factor (αH-Factor) of semiconductor quantum dot lasers epitaxially grown on silicon. Owing to the low density of threading dislocations and resultant high gain, an αH value of 0.13 that is rather independent of the temperature range (288 K–308 K) is measured. Above the laser threshold, the Linewidth Enhancement Factor does not increase extensively with the bias current which is very promising for the realization of future integrated circuits including high performance laser sources.

Heming Huang - One of the best experts on this subject based on the ideXlab platform.

  • influence of the polarization anisotropy on the Linewidth Enhancement Factor and reflection sensitivity of 1 55 μm inp based inas quantum dash lasers
    Applied Physics Letters, 2019
    Co-Authors: Bozhang Dong, Heming Huang, Frederic Grillot, Jianan Duan, Daehwan Jung, John E Bowers, Chen Shang, A B Sawadogo
    Abstract:

    This work investigates the effect of the polarization anisotropy on the Linewidth Enhancement Factor and the reflection sensitivity of InAs/InP quantum dash semiconductor lasers. The results show that the small Linewidth Enhancement Factor and high stability against external optical feedback are obtained for nanostructures oriented perpendicular to the cavity axis as opposed to those oriented parallel to the cavity axis. Effective simulations on the critical feedback level of these two lasers are also in agreement with experimental results. Such anisotropy is attributed to the polarization dependence of the transition matrix element in these quantum nanostructures.This work investigates the effect of the polarization anisotropy on the Linewidth Enhancement Factor and the reflection sensitivity of InAs/InP quantum dash semiconductor lasers. The results show that the small Linewidth Enhancement Factor and high stability against external optical feedback are obtained for nanostructures oriented perpendicular to the cavity axis as opposed to those oriented parallel to the cavity axis. Effective simulations on the critical feedback level of these two lasers are also in agreement with experimental results. Such anisotropy is attributed to the polarization dependence of the transition matrix element in these quantum nanostructures.

  • semiconductor quantum dot lasers epitaxially grown on silicon with low Linewidth Enhancement Factor
    Applied Physics Letters, 2018
    Co-Authors: Jianan Duan, Heming Huang, Frederic Grillot, Daehwan Jung, Zeyu Zhang, Justin Norman, John E Bowers
    Abstract:

    This work reports on the ultra-low Linewidth Enhancement Factor (αH-Factor) of semiconductor quantum dot lasers epitaxially grown on silicon. Owing to the low density of threading dislocations and resultant high gain, an αH value of 0.13 that is rather independent of the temperature range (288 K–308 K) is measured. Above the laser threshold, the Linewidth Enhancement Factor does not increase extensively with the bias current which is very promising for the realization of future integrated circuits including high performance laser sources.

  • semiconductor quantum dot lasers epitaxially grown on silicon with low Linewidth Enhancement Factor
    Applied Physics Letters, 2018
    Co-Authors: Jianan Duan, Heming Huang, Frederic Grillot, Daehwan Jung, Zeyu Zhang, Justin Norman, John E Bowers
    Abstract:

    This work reports on the ultra-low Linewidth Enhancement Factor (αH-Factor) of semiconductor quantum dot lasers epitaxially grown on silicon. Owing to the low density of threading dislocations and resultant high gain, an αH value of 0.13 that is rather independent of the temperature range (288 K–308 K) is measured. Above the laser threshold, the Linewidth Enhancement Factor does not increase extensively with the bias current which is very promising for the realization of future integrated circuits including high performance laser sources.This work reports on the ultra-low Linewidth Enhancement Factor (αH-Factor) of semiconductor quantum dot lasers epitaxially grown on silicon. Owing to the low density of threading dislocations and resultant high gain, an αH value of 0.13 that is rather independent of the temperature range (288 K–308 K) is measured. Above the laser threshold, the Linewidth Enhancement Factor does not increase extensively with the bias current which is very promising for the realization of future integrated circuits including high performance laser sources.

  • narrow spectral Linewidth in inas inp quantum dot distributed feedback lasers
    Applied Physics Letters, 2018
    Co-Authors: Jiana Dua, Heming Huang, Frederic Grillo, P J Poole, Cheng Wang
    Abstract:

    This paper reports on the spectral Linewidth of InAs/InP quantum dot distributed feedback lasers. Owing to a low inversion Factor and a low Linewidth Enhancement Factor, a narrow spectral Linewidth of 160 kHz (80 kHz intrinsic Linewidth) with a low sensitivity to temperature is demonstrated. When using anti-reflection coatings on both facets, narrow Linewidth operation is extended to high powers, believed to be due to a reduction in the longitudinal spatial hole burning. These results confirm the high potential of quantum dot lasers for increasing transmission capacity in future coherent communication systems.This paper reports on the spectral Linewidth of InAs/InP quantum dot distributed feedback lasers. Owing to a low inversion Factor and a low Linewidth Enhancement Factor, a narrow spectral Linewidth of 160 kHz (80 kHz intrinsic Linewidth) with a low sensitivity to temperature is demonstrated. When using anti-reflection coatings on both facets, narrow Linewidth operation is extended to high powers, believed to be due to a reduction in the longitudinal spatial hole burning. These results confirm the high potential of quantum dot lasers for increasing transmission capacity in future coherent communication systems.