外调制器直流偏压与输出光功率特性分析  

Characteristics of the direct current bias voltage and export light power of external modulator

作　　者：陈亦男[1] 张晓青[1] 李东[1] 

机构地区：[1]北京信息科技大学光电信息与通信工程学院,北京100192

出　　处：《北京信息科技大学学报（自然科学版）》2009年第2期82-86,共5页Journal of Beijing Information Science and Technology University

基　　金：北京市教委2008年科技发展基金项目(KM200811232012)

摘　　要：根据铌酸锂晶体的电光调制特性,采用折射率椭球方法分析了x切y传马赫-曾德强度调制器的调制原理。讨论了直流偏置电压对调制器输出相位的影响,给出直流偏压与调制器输出光功率之间的非线性特性关系式。当调制器工作在最佳的直流偏置点V_π/2附近时为近线性工作区;当直流偏压偏离V_π/2过多,则造成较大幅度的输出光功率变化,并导致微波光纤链路中所传输的电信号失真。实验表明,测试结果与理论分析相符。According to the electro-optic characteristics of LiNbO3 crystal, the refractive index ellipsoid method is adopted to analyze the modulation principle of the x-cut y conduction Mach-Zehnder intensity modulator. The effects of the direct current bias voltage on the export phase of the modulator are discussed, which produces a nonlinear characteristic equation of direct current bias voltage versus export light of modulator. When the modulator works nearby an optimal direct current bias point Vπ/2, there is an approximate linear output; when the direct current bias voltage deviates from Vπ/2 too far, the large variation of the export light power is produced, which leads to the distortion of the electronic signal in the microwave fiber link communication. The experiment shows that the test results coincide with the theoretical analysis.

关 键 词：光纤通信 外调制 强度调制 直流偏压 光功率 

分 类 号：TN929.1[电子电信—通信与信息系统]