Nonlinear Optics and Optical Switching in GaLAs and GaAs Near Half Band Gap

在过去的十年里， 光学性质 半导体，特别是GaAs， 研究了A1 GaAs 广泛接近其带隙，并且 已经应用于有限的 全光交换的成功。 然而，人们对它知之甚少。 物理学和应用 半导体接近一半的差距。 我们的初步结果 非线性定向耦合器具有 显示出了经典的 全光波导开关 低于带隙的一半。 基于 这个初步的结果， 建议调查第三个 体的阶非线性性质 GaAs和A1 GaAs的MQW样品 接近其带隙的一半，即 1）测量光谱 非线性依赖性 N2和双光子吸收 系数B2，求 由于间隙状态的增强， 激子ets; 2）使用下半部分 带隙非线性 演示全光交换 设备; 3）研究空间 孤子传播及其 潜在的逻辑应用 A1 GaAs器件; 4）研究是否 二阶级联 非线性会导致 三阶非线性

In the last decade the nonlinear optical properties of semiconductors, especially GaAs and A1GaAs have been studied extensively near their bandgap, and have been applied with limited success to all-optical switching. However little is known about the physics and applications of semiconductors near half their gap. Our preliminary results on a nonlinear directional coupler have shown the potential for classical all-optical waveguide switching below half the band gap. Based on this preliminary result, it is proposed to investigate the third order nonlinear properties of bulk and MQW samples of GaAs and A1GaAs near half their band gap, that is to: 1) measure the spectral dependence of both the nonlinearity n2 and two photon absorption coefficient B2, looking for enhancements due to gap states, excitons ets; 2) use the below half band gap nonlinearities to demonstrate all-optical switching devices; 3) investigate spatial soliton propagation, and its potential application to logic devices in A1GaAs; 4) study whether the cascading of second order nonlinearities can lead to large third order nonlinearities.