1.3-μm CW lasing characteristics of self-assembled InGaAs-GaAs quantum dots
1.3-μm CW lasing characteristics of self-assembled InGaAs-GaAs quantum dots
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DOI：
10.1109/3.831025
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发表时间：
2000-04-01
影响因子：
2.5
通讯作者：
Ishikawa, H
中科院分区：
文献类型：
--
作者：
Mukai, K;Nakata, Y;Ishikawa, H
本文研究了以自组装InGaAs-GaAs量子点为有源区的1.3 μ m半导体激光器的激射特性及其温度依赖性。利用分子束外延，通过低速率生长和InGaAs激光过生长的组合，成功地生长了高密度的1.3 μ m发射点，在25 ℃下，在5.4 mA的低阈值电流下发生1.3 μ m的地能级连续激光，实际腔长为300 μ m，两个面上都有高反射率涂层，从外量子效率和腔长之间的曲线的倾斜度估计激光器的内部损耗为约1.2cm（-1），每个点层的基态模式增益估计为1.0cm（-1），这与考虑点密度、非均匀展宽和均匀展宽的计算结果基本一致。阈值电流的特征温度T-O与腔长和激光器有源区点层数有关，在室温附近获得了82 K的To，并且作为注入电流的函数的自发辐射强度表明非辐射通道降低了温度特性。一项低温研究表明，如果消除非辐射复合过程，则可以获得具有低阈值电流（类似于1 mA）的无限T。本文的研究表明，量子点表面密度和辐射效率的提高是1.3 μ m量子点激光器发展的关键。
This paper presents the lasing properties and their temperature dependence for 1.3-mu m semiconductor lasers involving self-assembled InGaAs-GaAs quantum dots as the active region. High-density 1.3-mu m emission dots were successfully grown by the combination of low-rate growth and InGaAs-laser overgrowth using molecular beam epitaxy, 1.3-mu m ground-level CW lasing occurring at a low threshold current of 5.4 mA at 25 OC with a realistic cavity length of 300 mu m and high-reflectivity coatings on both facets, The internal loss of the lasers was evaluated to be about 1.2 cm(-1) from the inclination of the plots between the external quantum efficiency and the cavity length, The ground-level modal gain per dot layer was evaluated to be 1.0 cm(-1), which closely agreed with the calculation taking into account the dot density, inhomogeneous broadening, and homogeneous broadening, The characteristic temperature of threshold currents T-O was found to depend on cavity length and the number of dot layers in the active region of the lasers, A To of 82 K was obtained near room temperature, and spontaneous emission intensity as a function of injection current indicated that the nonradiative channel degraded the temperature characteristics. A low-temperature study suggested that an infinite T, with a low threshold current (similar to 1 mA) is available if the nonradiative recombination process is eliminated. The investigation in this paper asserted that the improvement in surface density and radiative efficiency of quantum dots is a key to the evolution of 1.3-mu m quantum-dot lasers.