New Methods of the Measurement of Electro-Optic Constants in Organic Materials

本研究的目的是发展一种新的测定电光常数和相关的非线性极化率的方法，并研究可用于电光和非线性光学器件的有用的有机材料。制作了一个用于测量的法布里-珀罗(EP)腔样品，在没有偏振器和检偏器对的情况下，采用纵向方案测量探测光的透射率变化，由于薄铝电极也用作FP腔的反射镜，因此可以以极高的灵敏度检测由于吸收变化或折射率变化引起的透射率变化，灵敏度可达10^~(-6)~(-6)。此外，这种薄膜样品还需要很低的外加电压(5~10V)。获得的信号由微型计算机进行处理和分析。另一种新的方法是使用马赫-曾德尔干涉仪。这种方法可以更清楚地区分EO常数的实部和虚部。为了提高干涉仪的信噪比和探测宽波长范围的电光信号，研制了一种反馈系统，测量了掺杂4-二乙氨基-4‘-亚硝基二苯乙烯(DeANS)的聚碳酸酯薄膜、聚二乙炔(PDA-3BCMU)薄膜以及包括几种聚合物在内的其他有机材料的电光常数。测量了掺入聚合物的半导体微晶的光致发光的电调制谱。

Purposes of this research are the development of a new method for the determination of the electro-optic (EO) constants and relevant nonlinear susceptibilities and the investigation of the useful organic materials which can be used the EO and nonlinear optical devices.A new convenient method is developed for the determination of the EO constants. A sample of Fabry-Perot (EP) cavity is prepared for the measurement, Without a polarizer and analyzer pair, transmittance change of probe light is measured using a longitudinal scheme, Since the thin aluminum electrodes are also used as mirrors of the FP cavity, the transmittance change due to either absorption change or eflactive index change can be detected with extremely high sensitivity down to 10^<-6>, In addition to these merits, low applied voltage (5-10 V) is sufficient for this thin film samples. The obtained signals are processed and analyzed by a microcomputer.Another new method using a Mach-Zehnder Interferometer is developed. The real and imaginary parts of the EO constants can be more clearly separated by this method. A feed-back system for the stabilization of the Interferometer is developed to improve signal to noise ratio and detect the EO signal at wide wavelength region.The EO constants of a thin film of polycarbonate doped with 4-diethylamino-4'-nitrostilbene (DEANS), a polydiacetylene (PDA-3BCMU) film, and other organic materials including several polymers are measured. The electromoduration spectrum of photoluminescence in semiconductor microcrystallites doped in polymer are also measured.