Development of a New Technique of Analyzing the Liquid Crystal Interface Reorientation Dynamics using Reflection FT-IR Time-Resolved Spectroscopy

在这项研究中，我们开发了两种新的光谱技术，具有空间和时间分辨率，以分析液晶在衬底表面的重定向动力学。首先，为了分析液晶分子在电场诱导的重定向转变过程中的基本片段过程，我们开发了一种新的200ns时间分辨率的步进扫描FT-IR时间分辨光谱（FT-IR TRS）。这种新技术的适用性已被证明适用于向列型液晶和铁电型近晶液晶。为了提高空间分辨率，使分析液晶表面重定向动力学成为可能，我们还开发了一种新的时间分辨偏振调制光谱椭偏系统（PMSE）。该系统具有100nm的空间分辨率和20mus的时间分辨率，使我们能够定量分析基板表面附近液晶的表面锚定效应和定向器重定向动力学。通过开发这些新的光谱技术，我们已经能够开辟液晶动态分析的新领域，可以深入到向列型和近晶型液晶中场诱导重定向转变的详细亚分子机制。本研究的结果有望为液晶显示器件的进一步发展做出贡献。

In this study, we have developed two new spectroscopic techniques, both with spacial and temporal resolution, in order to analyze the liquid crystal reorientation dynamics at the substrate surfaces.1.First, in order to analyze the elementary segmental processes of liquid-crystalline molecules during their electric-field induced reorientational transition, we have developed a new step-scan FT-IR time-resolved spectroscopy (FT-IR TRS) with 200ns time-resolution.Applicability of this new techniques has been demonstrated for nematic liquid crystals and for ferrolelectric smectic liquid crystals.2.To improve the spacial resolution and make it possible to analyze the liquid-crystal's surface reorientation dynamics, we have also developed a new time-resolved, polarization-modulated spectroellipsometry system (PMSE). This system, with 100nm spacial resolution and 20mus time-resolution, has enabled us to quantitatively analyze the surface anchoring effect and the director reorientation dynamics of liquid crystals in the very vicinity of substrate surfaces.By developing these new spectroscopic techniques, we have been able to open up a new field of dynamic analysis of liquid crystals that can penetrate into the detailed submolecular mechanisms of the field-induced reorientational transition in both nematic and smectic liquid crystals. The results obtained in this study are expected to be able to contribute to the further development of liquid crystal display devices.