Development of the mapping method for surface optical constants and its application to in-situ observation of surface photoinduced reaction.

目前的研究项目旨在通过理论和实验方法，在光催化剂薄膜表面光学常数的高分辨率光学外差微映射的发展。主要研究内容如下：1)光学外差微测系统开发的基础研究。为了建立基于光外差法的表面光学常数微映射，建立了一种采用AO调制器的探针激光束扫描系统和检测光拍频信号的电子器件，并研究了它们的基本特性。结果与下面描述的全息方法得到的结果进行了比较。为了研究在紫外光干扰下TiO2薄膜光催化剂的光致表面过程，采用了全息光栅法。本文认为，光催化作用下的反应物和/或反应中间体的微观分布可以通过相应的表面折射率的空间调制来探测。根据实验结果，提出了表面过程的动力学和表面传质系数等特征参数的估计方法。3)非线性电化学反应在铁电极上的时空传播研究了随表面光学常数变化的测试表面反应对铁电极非线性电化学振荡的影响。测量了电势在电解液中的时间依赖性传播和在铁电极上的时空模式形成。在反应方案中，当电阻串联插入恒电位器和铁电极之间时，氧化物还原的时空格局和电流振荡的脉冲形状都发生了变化。少

The present research project was aimed, by both theoretical and experimental approaches, at the development of a high resolution optical heterodyne micromapping of the surface optical constants at the photocatalyst thin films. Those major issues studied and the results obtained are as follows :1) Basic study for the development of the optical heterodyne micromapping system.In order to establish a micromapping of the surface optical constants based on the optical heterodyne method, a scanning system of a probe laser beam using an AO modulator and the electronics detecting the optical beat signal were setupped and their fundamental characteristics were studied. The results were compared with those obtained by the holographic method described below.2) In situ observation of the surface processes at thin-film TiO2 photocatalystHolographic grating method was undertaken in order to study the photoinduced surface processes as modeled at a TiO2 thin-film photocatalyst under the interfering uv- … More illumination. It was suggested that the microscopic distribution of reactants and/or reaction intermediates upon photocatalysis can be probed in terms of the corresponding spacial modulation of the surface refractive index. Based on the experimental results those characteristic parameters for the surface processes such as kinetics and the surface mass transfer coefficient were suggested to be estimated.3) Spatiotemporal propagation of non-linear electrochemical Reaction over iron electrodeNon-linear electrochemical oscillation of iron electrode was studied in terms of the test surface reaction accompanying the change in surface optical constants. The time dependent potential propagation into an electrolyte solution and spatiotemporal pattern formation on iron electrode were measured. Concerning the reaction scheme, when the resistance was inserted in series between the potentiostat and the iron electrode, the spatiotemporal pattern of the oxide reduction varied as well as the pulse shape of the current oscillation. Less