Engineering Research Equipment: Pulsed Laser System for Dynamical Studies of Photonic Materials

内布拉斯加大学物理与天文系将为我们购买一个脉冲激光系统，用于若干研究项目。所提出的脉冲激光系统包括：1)商用调q Nd:YAG泵浦激光器和二次谐波发生器，2)定制窄带宽脉冲染料激光器，以及3)光学表，探测器和适合用于高功率激光器的光学元件。与我们的连续波激光器（等于或大于1毫秒）相比，脉冲激光系统将用于在更短的时间尺度（等于或大于5纳秒）内进行动态测量，从而扩展了几个研究项目的范围。这些项目包括：1)光折变聚合物的动力学研究，阐明电荷的产生、捕获和输运过程；2)热释电材料在亚微秒时间尺度上由热释电和电光联合响应引起的全光调制，其中热释电效应占主导地位；3)光折变非线性法布里-珀罗标准子的动力学响应，其表现出强度依赖的不对称传输，并可能表现出光学双稳定性。4)光折变材料中调制吸收的光谱学和动力学，以获得能量、寿命、横截面和其他有关（“深”和“浅”）陷阱的信息；5)聚合物/晶体纳米复合材料的非线性光学效应。＊＊＊

9500106 Ducharme The Department of Physics and Astronomy at the University of Nebraska will purchase a pulsed laser system for us with several research projects. The proposed pulsed laser system consists of: 1) a commercial Q-switched Nd:YAG pump laser and second harmonic generator, 2) a custom narrow bandwidth pulsed dye laser, and 3) an optical table, detectors, and optical elements suitable for use with high power lasers. The pulsed laser system will be used to conduct dynamical measurements on a much shorter time scale (equal to or greater than 5 ns) than is possible with our CW lasers (equal to or greater that 1 ms), extending the scope of several research projects. These projects include: 1) Dynamical studies of photorefractive polymers elucidating charge generation, trapping, and transport processes, 2) All-optical modulation caused by combined pyroelectric and electro-optic response in pyroelectric materials in the sub- microsecond time scale during which the pyroelectric effects are dominant, 3) Dynamical response of the photorefractive nonlinear Fabry-Perot etalon which exhibits intensity dependent asymmetric transmission and may exhibit optical bistability, 4) Spectroscopy and dynamics of modulated absorption in photorefractive materials to obtain energies, lifetimes, cross sections, and other information concerning ("deep" and "shallow") traps, and 5) Nonlinear optical effects on polymer/crystal nanocomposites. ***