Semiconductor Physics and Photonics

本文的研究工作主要包括三个方面：MBE生长 非线性材料，这些材料的半导体物理， 以及使用这些材料的非线性器件。 注意力将首先集中在生长砷化镓基结构上 和设备，如散装，单。和多个量子阱样品， 法布里。珀罗标准具与单片镜，以及开始 用于非线性波导和量子点结构的材料。 将研究样品的光学性质， 特别强调的线性和非线性光学性质， 激子下面的光谱区域。 研究吸收尾部， 它在高激发下的饱和不仅非常有趣， 物理学，但也有助于表征生长的质量 样品，并为最佳的设备设计和操作必不可少的。 吸收尾，载流子寿命和偏振依赖性的 带隙非线性将作为量子 阱宽度、生长条件和器件设计。 将使用微光刻和各向异性蚀刻技术， 为了制造非线性波导结构 耦合器和马赫曾德尔干涉仪，以及阵列的 半导体标准具控制载流子寿命的方法， 因此，非线性器件的响应时间将是 调查，和设备将被设计为低。功率 工作在相对较低的速度和超快的光开关。

The research effort proposed here consists of three parts: MBE growth of nonlinear materials, semiconductor physics of those materials, and nonlinear devices using those materials. Attention will be focused initially on growing GaAs.based structures and devices such as bulk, single. and multiple.quantum.well samples, Fabry.Perot etalons with monolithic mirrors, as well as starting material for nonlinear waveguides and quantum dot structures. The optical properties of the samples will be studied, with special emphasis on the linear and nonlinear optical properties in the spectral regions below the exciton. Studying the absorption tail and its saturation under high excitation is not only very interesting physics, but also helpful for characterizing the quality of the grown samples, and essential for optimum device design and operation. Absorption tail, carrier lifetime, and polarization dependence of the bandgap nonlinearities will be investigated as functions of quantum well widths, growth conditions, and device design. Microlithography and anisotropic etching techniques will be used, to fabricate nonlinear waveguide structures such as directional couplers and Mach.Zehnder interferometers, as well as arrays of semiconductor etalons. Methods to manipulate the carrier lifetime and, hence, the response time of the nonlinear devices will be investigated, and devices will be designed for both low.power operation at relatively low speed and forultrafast optical switching.