Optical Microstructures and Their Application to SpontaneousEmission Inhibition and Semiconductor Micro-Lasers (ResearchInitiation Award)

提出了一种实验研究方案，以研究利用微介质结构抑制半导体中的自发辐射，并探索各种实现具有微型环形腔的半导体微激光器。抑制自发辐射由于其在低阈值激光器中的潜在应用而引起人们的极大兴趣。我们最近在理论上证明，在半导体中嵌入一层薄层可以大大降低激子的自发发射率.折射率材料。对这一效应进行了实验研究。这项实验将涉及用时间分辨的方法测量薄的GaAs或InP量子阱或掺Yb的半导体中的激子衰变。周围环绕着低折射率的材料。稍后，类似的研究将扩展到线状介质结构。所需的微结构将通过选择性蚀刻技术来制造。同样的技术可以用来制造半导体微环激光器，最近被证明具有较低的(光泵浦)阈值。然而，从这种激光器中获得输出的好方法还没有实现。提出了一种实验来研究这种激光器与波导的耦合作为一种输出耦合方法。将探索各种几何结构和有源层，以确定这种激光器的最佳再启动。

An experimental research program is proposed to study inhibition of spontaneous emission in semiconductors using micro dielectric structures and to explore various realizations of semiconductor micro-lasers with microscopic ring cavities. The inhibition of spontaneous emission is of great interest because of its potential application to low- threshold lasers. We showed recently theoretically that the spontaneous emission rates of excitons in a semiconductor can be drastically reduced by embedding a thin layer of the semiconductor in low- refractive-index materials. An experimental study of this effect is proposed. The experiment will involve time-resolved measurement of excitonic decay in thin GaAs or InP quantum wells, or Yb-doped semiconductors, surrounded by materials of low refractive indices. Later, similar studies will be extended to wire-like dielectric structures. The microstructures required will be fabricated via a selective- etching technique. The same technique can be used to fabricate semiconductor micro-ring lasers, which were recently demonstrated to have low (optically pumped) thresholds. A good way to obtain output from such lasers, however, has not been achieved. An experiment is proposed to investigate the coupling of such lasers to waveguides as an output coupling method. Various geometries and active layers will be explored to determine the optimal relaization of such lasers.