SGER: Optical Parametric Processes in Ferroelectric Liquid Crystal Filled Capillary Tube Waveguides

发展了一类新的二阶非线性光学材料：X(2)铁电液晶。传统的氟碳化合物很容易形成各种厚度的低光损耗的极化膜，并已被证明是光波导器件。新的X(2)氟碳化合物结合了传统氟碳化合物的可加工性和有用量级的热力学稳定的非线性光学敏感性。此外，光学特性，如双折射、介电常数和非线性光学特性，可通过化学合成和混合高度定制。在这个探索性研究的小赠款中，使用厘米长的诱人可能性，我们将研究用于光学参数过程的填充了X(2)FLC的UM内径毛细管。将在这项工作中回答的关键问题包括：1)毛细管中的本征导向器结构是什么-是极化矢量场PERAL，如何控制它？2)对于FLC芯的光波导有哪些可能的相位匹配方案？实验考察了FLC在毛细管中的取向，以及液晶相序列、螺旋螺距、倾斜角度、毛细管制备对对准特性的影响将被确定。使用导向器对准信息，通过求解相对介电常数与位置有关的波动方程，精确模拟了二次谐波的产生过程。非线性极化率。最后，利用X(2)FLC混合显示技术MX-5679实现了近红外辐射的倍频，将对厘米长的毛细管进行实验研究。

A new class of second order nonlinear optical (NLO) materials has been developed: X(2) ferro- electric liquid crystals (FLCs). Conventional FLCs readily form low- light-loss polar films in a wide range of thicknesses, and have been demonstrated as optical waveguides. The new X(2) FLCs combine the processibility of conventional FLCs with thermodynamically stable NLO susceptibility of useful magnitude. In addition, optical properties such as birefringence, dielectric permittivity, and NLO properties are highly customizable by chemical synthesis and mixing. In this Small Grant for Exploratory Research, the attractive possibility of using centimeter long, um inner diameter capillary tubes filled with X(2) FLCs for optical parametric processes will be investigated. Key questions which will be answered in this work include the following: 1) What is the intrinsic director structure in the capillary tubes--is the polarization vector field polar, and how can it be controlled? 2) What are possible phase matching schemes for FLC-cored optical waveguides? FLC alignment in capillary tubes will be examined experimentally, and the effect of FLC material parameters such as liquid crystal phase sequence, helix pitch, tilt angle, and capillary tube preparation on alignment characteristics will be determined. Using director alignment information, second harmonic generation processes will be accurately modeled by solving the wave equation with position dependent relative permittivity and nonlinear polarizability. Finally, frequency doubling of near-infrared radiation using the X(2) FLC mixture Displaytech MX-5679 in um inner diameter, centimeter long capillary tubes will be investigated experimentally.