电光调制系统设计

Design of Electro-optic Modulation System

调制是光电系统中的一个重要环节。光辐射的调制是指改变光波振幅、强度、相位或频率、偏振等参数使之携带信息的过程。调制的目的是对所需处理的信号或被传输的信息进行某种形式的变换,使之便于处理、传输和检测。目前用得较多的是电光调制、声光调制等方法。文中介绍的电光调制系统主要是验证电光调制原理以及介绍电光调制在激光通信方面的应用,通过此系统了解晶体电光调制的原理和实验方法,以便在此系统中测量晶体的半波电压、电光系数和消光比等参量。

Modulation is an important link in the photo-electric system. Modulation of light refers to changing parameters of light wave such as amplitude, intensity, and phase, frequency, polarization, etc. to make it carry message. The purpose of modulation is to make certain transform of signal that need to be processed to transmit information, make it convenient to deal with, transmit and detect. At present electro-optic modulation and sound-optic modulation etc. are used more and more. Electro-optic modulation system which is introduced in this paper is to describe electro-optic modulation principle and recommend its application for laser communication mainly. Through this system, we can understand crystal electro-optic modulation principle and experiment method. We should master how to measure half wave voltage of the crystal, the electro-optic coefficient and disappearing ratio in this system, etc.