The Experts below are selected from a list of 279 Experts worldwide ranked by ideXlab platform
M Hopkinson - One of the best experts on this subject based on the ideXlab platform.
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low threshold current density and negative Characteristic Temperature 1 3 μm inas self assembled quantum dot lasers
Applied Physics Letters, 2007Co-Authors: T J Badcock, K M Groom, M Hopkinson, D J Mowbray, M S Skolnick, Huiyun Liu, R J Royce, Q JiangAbstract:By combining optimized growth of the GaAs spacer layers and p-type modulation doping of the quantum dots, a 1.3μm emitting self-assembled quantum dot laser exhibiting both a low threshold current density and negative-T0 Temperature behavior at room Temperature is achieved. Spontaneous emission measurements provide no evidence for enhanced Auger recombination in doped devices. The negative T0 exhibited by the doped device is consistent with a delayed thermalization of carriers within the quantum dot ensemble.
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observation and modeling of a room Temperature negative Characteristic Temperature 1 3 mu m p type modulation doped quantum dot laser
IEEE Journal of Quantum Electronics, 2006Co-Authors: Chaoyuan Jin, T J Badcock, K M Groom, D J Mowbray, Huiyun Liu, R J Royce, M HopkinsonAbstract:A room-Temperature negative Characteristic Temperature (T0 ) and ultralow threshold current density (Jth) of 48 Amiddotcm-2 are demonstrated for a 1.3-mum InAs quantum dot laser. These Characteristics are obtained by combining a high-growth-Temperature GaAs spacer layer with p-type modulation doping of the quantum dots in multiple layer dot-in-a-well structures. Through a comparison of p-doped and undoped devices, a photon coupling mechanism is proposed to account for the different Temperature dependences of Jth for the two devices. Numerical simulations based on a rate equation model, which includes photon coupling between ground and excited quantum dot states, are performed. The simulations are able to account for the very different Temperature-dependent Jth behavior of the doped and undoped device
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1 3 micro sign m inas gaas quantum dot laser with low threshold current density and negative Characteristic Temperature above room Temperature
Electronics Letters, 2006Co-Authors: T J Badcock, H Y Liu, K M Groom, Chaoyuan Jin, M Gutierrez, M Hopkinson, D J Mowbray, M S SkolnickAbstract:The combination of a high-growth-Temperature GaAs spacer layer and p-type modulation doping has been utilised to obtain a low-threshold-current-density, high-Temperature-stability 1.3 µm InAs/GaAs quantum-dot laser. A room-Temperature threshold current density of 48 A/cm2 and a negative Characteristic Temperature over the Temperature range from −50 to 40°C is achieved for a five-layer device with as-cleaved facets.
T J Badcock - One of the best experts on this subject based on the ideXlab platform.
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low threshold current density and negative Characteristic Temperature 1 3 μm inas self assembled quantum dot lasers
Applied Physics Letters, 2007Co-Authors: T J Badcock, K M Groom, M Hopkinson, D J Mowbray, M S Skolnick, Huiyun Liu, R J Royce, Q JiangAbstract:By combining optimized growth of the GaAs spacer layers and p-type modulation doping of the quantum dots, a 1.3μm emitting self-assembled quantum dot laser exhibiting both a low threshold current density and negative-T0 Temperature behavior at room Temperature is achieved. Spontaneous emission measurements provide no evidence for enhanced Auger recombination in doped devices. The negative T0 exhibited by the doped device is consistent with a delayed thermalization of carriers within the quantum dot ensemble.
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observation and modeling of a room Temperature negative Characteristic Temperature 1 3 mu m p type modulation doped quantum dot laser
IEEE Journal of Quantum Electronics, 2006Co-Authors: Chaoyuan Jin, T J Badcock, K M Groom, D J Mowbray, Huiyun Liu, R J Royce, M HopkinsonAbstract:A room-Temperature negative Characteristic Temperature (T0 ) and ultralow threshold current density (Jth) of 48 Amiddotcm-2 are demonstrated for a 1.3-mum InAs quantum dot laser. These Characteristics are obtained by combining a high-growth-Temperature GaAs spacer layer with p-type modulation doping of the quantum dots in multiple layer dot-in-a-well structures. Through a comparison of p-doped and undoped devices, a photon coupling mechanism is proposed to account for the different Temperature dependences of Jth for the two devices. Numerical simulations based on a rate equation model, which includes photon coupling between ground and excited quantum dot states, are performed. The simulations are able to account for the very different Temperature-dependent Jth behavior of the doped and undoped device
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1 3 micro sign m inas gaas quantum dot laser with low threshold current density and negative Characteristic Temperature above room Temperature
Electronics Letters, 2006Co-Authors: T J Badcock, H Y Liu, K M Groom, Chaoyuan Jin, M Gutierrez, M Hopkinson, D J Mowbray, M S SkolnickAbstract:The combination of a high-growth-Temperature GaAs spacer layer and p-type modulation doping has been utilised to obtain a low-threshold-current-density, high-Temperature-stability 1.3 µm InAs/GaAs quantum-dot laser. A room-Temperature threshold current density of 48 A/cm2 and a negative Characteristic Temperature over the Temperature range from −50 to 40°C is achieved for a five-layer device with as-cleaved facets.
C Y Liu - One of the best experts on this subject based on the ideXlab platform.
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rate equation model of the negative Characteristic Temperature of inas gaas quantum dot lasers
Journal of Applied Physics, 2007Co-Authors: Cunzhu Tong, S F Yoon, C Y LiuAbstract:The negative Characteristic Temperature of InAs∕GaAs quantum dot lasers is studied using a rate equation model. It is found that the decrease in the total contribution to lasing following a decrease in Temperature is the reason for the occurrence of negative Characteristic Temperature in these lasers. The Temperature corresponding to the occurrence of negative Characteristic Temperature is determined by the carrier escape rate from the quantum dots to the wetting layer or cap layer, carrier recombination lifetime, and rate of carrier loss due to deviation from (quasi-) Fermi equilibrium. The negative Characteristic Temperature in InAs∕GaAs quantum dot lasers does not occur under conditions of low carrier recombination lifetime and high quantum dot energy level occupation.
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Ridge Width Effect on the Characteristic Temperature of GaInNAs Triple Quantum Well Ridge Waveguide Lasers
2005 Pacific Rim Conference on Lasers & Electro-Optics, 1Co-Authors: C Y Liu, S.f. Yoon, W.j. Fan, Z.z. Sun, R.j.w. TewAbstract:GaInNAs triple quantum well lasers, grown using metalorganic chemical vapor deposition, were fabricated. The lasers worked under continuous wave operation from 20 ~ 100 °C. Significant improved Characteristic Temperature has been observed as the ridge width narrows.
L V Asryan - One of the best experts on this subject based on the ideXlab platform.
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Internal-loss-limited maximum operating Temperature and Characteristic Temperature of quantum dot laser
Laser Physics Letters, 2007Co-Authors: L Jiang, L V AsryanAbstract:Carrier-density-dependent internal optical loss sets an upper limit for operating Temperatures and considerably reduces the Characteristic Temperature of a quantum dot laser. Such internal loss also constrains the shallowest potential well depth and the smallest tolerable size of a quantum dot at which the lasing can be attained. At the maximum operating Temperature or when any parameter of the structure is equal to its critical tolerable value, the Characteristic Temperature drops to zero.
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Maximum operating Temperature and Characteristic Temperature of a quantum dot laser in the presence of internal loss
Quantum Dots Particles and Nanoclusters IV, 2007Co-Authors: L Jiang, L V AsryanAbstract:Carrier-density-dependent internal optical loss sets an upper limit for operating Temperatures and considerably reduces the Characteristic Temperature of a quantum dot laser. Such internal loss also constrains the shallowest potential well depth and the smallest tolerable size of a quantum dot at which the lasing can be attained. At the maximum operating Temperature or when any parameter of the structure is equal to its critical tolerable value, the Characteristic Temperature drops to zero.
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Characteristic Temperature of a tunneling-injection quantum dot laser
2007 International Semiconductor Device Research Symposium, 2007Co-Authors: Dae-seob Han, L V AsryanAbstract:High Temperature stability of threshold current has been predicted for the semiconductor quantum dot (QD) laser. An ideal situation would be Temperature-insensitive threshold current density j0 i.e. the Characteristic Temperature (a widely-accepted figure of merit of any diode laser from the viewpoint of Temperature-stability of its y'th) defined as T0=(partln jth/partT)-1. In this paper the authors study the effect of out-tunneling leakage of carriers from QDs and hence of recombination outside QDs on the T-dependence of j0. The authors show that, even in the presence of such leakage, T0 remains very high. The authors analyze T0 versus the parameters of a GalnAsP/InP heterostructure lasing near 1.55 mum.
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Theory of threshold Characteristics of semiconductor quantum dot lasers
Semiconductors, 2004Co-Authors: L V Asryan, R A SurisAbstract:A comprehensive theory of threshold Characteristics of quantum dot (QD) lasers, which provides a basis for optimization of their design, is reviewed. The dependences of the gain, transparency current, threshold current, Characteristic Temperature, and multimode generation threshold on the parameters of the QD ensemble (surface density and size dispersion of QDs), cavity (stripe length and thickness of the waveguide region), heterocontacts (band offsets), and Temperature are considered in detail. The limiting Characteristics of the laser (optimum structure parameters, minimum threshold current density, and Characteristic Temperature of the optimized structure) are discussed at length. The results of the analysis may serve as direct recommendations for the development of QD lasers that significantly outperform the semiconductor lasers currently in use.
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Characteristic Temperature of quantum dot laser
Electronics Letters, 1997Co-Authors: L V Asryan, R A SurisAbstract:The Characteristic Temperature of a quantum dot laser, T0, has been calculated for the first time considering carrier recombination in the optical confinement layer and violation of the charge neutrality in QDs. T0 is shown to fall off profoundly with increasing Temperature, which is in line with the available experimental results.
Tetsuya Kawanishi - One of the best experts on this subject based on the ideXlab platform.
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High Characteristic Temperature for ridge-waveguide laser with a highly stacked InAs quantum dot structure
2016 International Semiconductor Laser Conference (ISLC), 2016Co-Authors: Kouichi Akahane, Atsushi Matsumoto, Toshimasa Umezawa, Naokatsu Yamamoto, Tetsuya KawanishiAbstract:A ridge-waveguide laser with highly stacked InAs quantum dot structure based on strain compensation technique was fabricated. The threshold current of this laser was decreased to approximately 75 mA without coating the facet mirror. A high Characteristic Temperature of over 100 K was obtained using this laser.
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high Characteristic Temperature of highly stacked quantum dot laser for 1 55 mu m band
IEEE Photonics Technology Letters, 2010Co-Authors: Kouichi Akahane, Naokatsu Yamamoto, Tetsuya KawanishiAbstract:We fabricated broad-area laser diodes comprising 30-layer stacks of InAs quantum dots (QDs) by using strain compensation. The devices exhibited ground-state lasing at 1529 nm in pulsed mode with a high Characteristic Temperature of 113 K around room Temperature (20°C-80°C). Ground-state lasing was achieved because of the high QD density afforded by strain compensation.