电光相位调制器半波电压闭环测量方法  

Closed loop measurement of half-wave voltage of an electrooptical phase modulator

作　　者：陈杏藩[1] 曾宪超[2] 周虎[1] 王磊[1] 

机构地区：[1]浙江大学光电工程信息学系,浙江杭州310027 [2]北京航天控制仪器研究所,北京100854

出　　处：《浙江大学学报（工学版）》2014年第3期555-560,共6页Journal of Zhejiang University：Engineering Science

基　　金：浙江省自然科学基金资助项目(LQ12F03010);武器装备预研基金资助项目(9140A09010412JW0401);中央高校基本科研业务费专项资金资助项目(2012QNA5002)

摘　　要：以光纤Sagnac干涉仪为基础,利用其时延差分的调制特性,建立一套电光相位调制器半波电压的闭环测试方法,消除了由光强等低频波动引入的测量误差.设计相应的调制解调的闭环数字方程,完成了仿真实验.仿真结果表明:所设计的闭环方法能快速地追踪半波电压,其测量精度和系统的低频波动无关,测量精度受制于测试系统的宽谱噪声信号.搭建实验系统,实现闭环算法,相位调制器样品的半波电压测试结果表明:在200Hz的测试频率下该实验系统的测量相对精度优于1.8×10-5,1s平均测试的相对精度优于1.1×10-5,实验系统测量精度受限于被测相位调制器的温度敏感性和环境参数的稳定性.该测量方法能够精确测量高精度光纤传感系统中相位调制器的半波电压,也可应用于设计高精度的温度传感器.By employing the time delay modulation characteristic of the fiber optical Sagnac interferometer, a closed loop measurement method for half-wave voltage（HWV）of an eletrooptical phase modulator was designed.Such closed loop method eliminates the influence of optical signal drift on the measure result. The digital function of the closed control loop for modulation and demodulation was designed for simulation,which shows good HWV tracking performance.Simulation results also confirm its immunity to low frequency drift error in the system,and the measure accuracy depends on the noise power only.An experiment system was set up to implement the algorithm.The test results show that：the HWV measure precision is better than 1.8×10-5 under 200Hz sampling frequency,and it is better than 1.1×10-5 for one second average,which is restricted by the temperature sensitive of the modulator and the unstability of the test environment.The proposed method can measure the HWV of phase modulator with good precision, thus improving the performance of the fiber optical sensor,which can be also employed in precise temperature measurement with fast speed.

关 键 词：相位调制器 半波电压 SAGNAC干涉仪 闭环测试 

分 类 号：O431[机械工程—光学工程]