Study of Saturable Nonlinear Interfaces (Supplemental Funding for Women, Minority and Disabled Engineering Research Assistants)

本提案将研究高强度光在非线性界面上的反射和透射现象，并基于观察到的效应开发光学器件。由于染料溶液具有极大的非线性，本文将利用连续波氩激光器对其进行非线性介质研究。这提供了一个独特的机会来测试现有的非线性界面效应理论，如双稳性，沿界面的光束捕获，强度相关的k向量。为了研究饱和吸收界面上更复杂的反射动力学，将使用单次发射诊断技术测量反射和入射超短脉冲的振幅和相位。飞秒分辨荧光以及探测脉冲的振幅和相位反射将用于监测界面后非线性介质的复杂磁化率。一种新的时间分辨飞秒成像技术将监测与强度相关的k矢量的反射模式。将研究的直接应用包括非线性有源和无源开关（对锁模应用很重要），能量或强度限制器以及感应对称波导。

This proposal will study phenomena associated with the reflection and transmission of high intensity light at nonlinear interfaces, and the development of optical devices based on the observed effects. Because of its giant nonlinearities, a dye solution will be investigated as the nonlinear medium, using a CW argon laser. This offers a unique opportunity to test existing theories on nonlinear interface effects, such as bistability, beam trapping along the interface, intensity dependent k-vector. To study the more complex dynamics of reflection at saturable absorption interface, the amplitude and phase of reflected and incident ultrashort pulses will be measured, using single shot diagnostic techniques. Femtosecond resolved fluorescence as well as the reflection in amplitude and phase of a probe pulse will be used to monitor the complex susceptibility of the nonlinear medium behind the interface. A new time resolved femtosecond imaging technique will monitor the reflected pattern of intensity dependent k vectors. Direct applications that will be investigated include the nonlinear switch active and passive (important for mode-locking applications), an energy or intensity limiter, and an induced symmetrical waveguide.