Marko Igor P, Broderick Christopher A, Jin Shirong, Ludewig Peter, Stolz Wolfgang, Volz Kerstin, Rorison Judy M, O'Reilly Eoin P, Sweeney Stephen J
Advanced Technology Institute and Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom.
Department of Electrical and Electronic Engineering, University of Bristol, Bristol BS8 1UB, United Kingdom.
Sci Rep. 2016 Jul 1;6:28863. doi: 10.1038/srep28863.
Electrically pumped GaAsBi/GaAs quantum well lasers are a promising new class of near-infrared devices where, by use of the unusual band structure properties of GaAsBi alloys, it is possible to suppress the dominant energy-consuming Auger recombination and inter-valence band absorption loss mechanisms, which greatly impact upon the device performance. Suppression of these loss mechanisms promises to lead to highly efficient, uncooled operation of telecommunications lasers, making GaAsBi system a strong candidate for the development of next-generation semiconductor lasers. In this report we present the first experimentally measured optical gain, absorption and spontaneous emission spectra for GaAsBi-based quantum well laser structures. We determine internal optical losses of 10-15 cm(-1) and a peak modal gain of 24 cm(-1), corresponding to a material gain of approximately 1500 cm(-1) at a current density of 2 kA cm(-2). To complement the experimental studies, a theoretical analysis of the spontaneous emission and optical gain spectra is presented, using a model based upon a 12-band k.p Hamiltonian for GaAsBi alloys. The results of our theoretical calculations are in excellent quantitative agreement with the experimental data, and together provide a powerful predictive capability for use in the design and optimisation of high efficiency lasers in the infrared.
电泵浦GaAsBi/GaAs量子阱激光器是一类很有前景的新型近红外器件，通过利用GaAsBi合金不同寻常的能带结构特性，可以抑制主要的耗能俄歇复合和价带间吸收损耗机制，而这些机制会极大地影响器件性能。抑制这些损耗机制有望实现电信激光器的高效、非制冷运行，使GaAsBi系统成为下一代半导体激光器开发的有力候选者。在本报告中，我们展示了首个基于GaAsBi的量子阱激光结构的光学增益、吸收和自发发射光谱的实验测量结果。我们确定内部光学损耗为10 - 15 cm⁻¹，峰值模式增益为24 cm⁻¹，对应于电流密度为2 kA cm⁻²时约1500 cm⁻¹的材料增益。为补充实验研究，我们使用基于GaAsBi合金的12带k.p哈密顿量的模型，对自发发射和光学增益光谱进行了理论分析。我们的理论计算结果与实验数据在定量上高度吻合，共同为红外高效激光器的设计和优化提供了强大的预测能力。
