LiNbO3晶体电光效应的研究.doc

摘  要：随着光纤通讯技术迅猛发展，作为光电调制器的主要材料LiNbO3晶体的应用越来越广泛，其物理本质是LiNbO3晶体电光效应，由于LiNbO3晶体电光效应分为纵向和横向，且与LiNbO3晶体材料晶轴方向有关。对于LiNbO3晶体的o光和e光折射率出现了多种表达式，电光调制的半波电压也出现了多种形式。针对这些问题，研究工作从电光效应的物理本质入手，进行深入研究，得到LiNbO3晶体的o光和e光折射率不仅与波长有关，而且与温度也有关，因此产生了多种表达形式；对LiNbO3晶体的纵向和横向电光效应分析得出电光调制的半波电压与晶轴方向有关，得到了完整的横向电光效应半波电压公式。并利用实验室条件，巧妙地选用1/4波长片，在600V的电源条件下完成了LiNbO3晶体横向电压效应，得到半波电压为360V，与德国Leybold 实验仪器得到的实验结果相似，并估计出LiNbO3晶体样品材料长度与厚度之比为7.6，与实验样品实际尺寸比相吻合。

关键词：信息光学；电光效应；LiNbO3晶体

Abstract：With the development of the communication technology for optical fiber, the application of LiNbO3 is more and more widen as the main material of photoelectric modulator. The physical essence is the electro-optic effect of LiNbO3 crystal. The electro-optic effect of LiNbO3 crystal could be divided two kinds. One of them is transverse electro-optic effect. Another is longitudinal electro-optic effect. For the transverse electro-optic effect the result is relation of the axis direction in LiNbO3 crystal. There are many different values of no and ne in many references. There are over three expressions of the half-wave voltage in transverse electro-optic effect in many references. The study is from two problems. The results are shown that the refractive indexes of no and ne are the functions of the wavelength and the temperature. The transverse electro-optic effect is relation of the axis direction in LiNbO3 crystal. The experiment for measurement the half-wave voltage based on the transverse electro-optic effect had finish with smart method. The smart method is used the 1/4 wavelength plate in the optical path. The half-wave voltage is 360V that is similar to the result measured with German Leybold experimental apparatus. The ratio between the length and the thickness is estimated. The ratio is 7.6 and agrees with the result of the actual size. 

Key words: Information Optics; Electro-Optic effect; LiNbO3 crystal