EAGER: Spatial and Spectral Beam Control of Angled-Cavity Distributed-Feedback Quantum Cascade Lasers

本研究的目的是研究一种新型的广域半导体激光器的工作原理，称为β型分布反馈激光器。该方法包括通过倾斜腔的横向模式选择机制和通过β型分布反馈光栅的纵向模式选择机制的数值和实验研究。本研究的智力价值在于对β型分布反馈的模式选择机制有了更深入的了解。横向模式的选择将作为空腔倾斜角、脊宽、空腔长度和侧壁垂直度的函数进行研究。通过改变耦合强度来研究纵向模态的选择。最后，将优化设计应用于最佳量子级联增益介质，以演示室温单模工作时的最高峰值功率。所提出的研究的更广泛的影响源于β型分布式反馈激光器的潜力，该激光器为所有类型的半导体激光器的功率缩放提供了一种具有成本效益的方法，同时保持单模发射的优异光束质量，这为社会提供了巨大的利益，鉴于目前半导体激光器在消费市场上的扩散。拟议的研究活动的结果将在同行评议的期刊、专业会议和非技术出版物上传播。一些结果也将被汇编成研究生和本科课程的课堂材料。

The objective of this research is to investigate the operation principle of a new type of broad-area semiconductor lasers, termed beta-type distributed feedback lasers. The approach involves numerical and experimental investigations of the lateral mode selection mechanism through the angled cavity and the longitudinal mode selection mechanism through the beta-type distributed feedback grating.The intellectual merit of the proposed research is that a deeper understanding about the mode selection mechanism of beta-type distributed feedback will be obtained. The lateral mode selection will be investigated as functions of the cavity tilt angle, ridge width, cavity length, and sidewall verticalness. The longitudinal mode selection will be studied by changing the coupling strength. Finally, the optimal design will be applied to the best quantum cascade gain medium to demonstrate the highest peak power in room temperature single mode operation.The broader impacts of the proposed research stem from the potential that the beta-type distributed feedback laser offers a cost effective approach for power scaling of all types of semiconductor lasers while maintaining excellent beam quality with single mode emission, which offers immense benefit to the society, given the current proliferation of semiconductor lasers in the consumer market. The result of the proposed research activity will be disseminated in peer reviewed journals, professional conferences, and non-technical publications. Some results will also be compiled into classroom materials for both graduate and undergraduate courses.