Quantum Wire Nanostructures in Multiple Quantum Well OpticalWaveguides: Enhanced Nonlinear Optical Interactions

这是一种将量子线纳米结构引入到砷化镓多量子阱(MQW)光波导结构中以增强非线性光学相互作用的建议。制备量子线的主要技术是使用聚焦离子束(Fib)直接写入多量子波光波导，然后进行快速热退火来感应杂质诱导层或成分无序(混合)。还计划使用这种FIB混合技术来定义和形成通道光波导。除了使用FIB混合，还将研究电场诱导的多量子井区的周期性表面限制以形成量子线。量子线有望提供更强的非线性响应，而光波导的存在将在长传输长度上提供高光功率密度和低输入功率。这些综合效应可以使非线性相互作用在较低的功率水平下更加有效，从而适合于应用。将对GaAlAs多量子阱样品进行广泛的实验表征，包括扫描隧道和原子力显微镜(STM，AFM)，光子扫描隧道显微镜(PSTM)，基于聚焦离子束的亚微米二次离子质谱仪、横截面透射电子显微镜(XTEM)、空间分辨光致发光和拉曼光谱、以及皮秒时间尺度上的四波混频和泵浦探测实验。

This is a proposal for incorporating quantum wire nanostructures into gallium aluminum arsenide multiple quantum well (MQW) optical waveguide structures in order to enhance nonlinear optical interactions. The primary technique to be pursued for fabrication of quantum wires is to use focused ion beam (FIB) direct writing onto MQW optical waveguides followed by rapid thermal annealing to induce impurity-induced layer or compositional disordering (mixing). Use of this FIB mixing technique to define and form channel optical waveguides is also planned. In addition to using FIB mixing, electric field-induced periodic surface confinement in multiple quantum well regions to form quantum wires will also be investigated. Quantum wires are expected to provide a stronger nonlinear response while the presence of the optical waveguide provides high optical power densities with low input power over long propagation lengths. These combined effects may make the nonlinear interactions more efficient at lower power levels and thus suitable for applications. Extensive experimental characterization will be performed on GaAlAs MQW samples, including scanning tunneling and atomic force microscopy (STM, AFM), photon scanning tunneling microscopy (PSTM), focused ion beam based sub-micron secondary ion mass spectroscopy, cross-sectional transmission electron microscopy (xTEM), spatially resolved photoluminescence and Raman spectroscopies, and four-wave mixing and pump-probe experiments on the picosecond time scale.