发光学报2017，Vol.38Issue(3)：395-401,7.DOI:10.3788/fgxb20173803.0395
采用3×3耦合器的分布反馈式光纤激光传感器解调技术
Demodulation Technology of Distributed Feedback Fiber Laser Sensor Based on 3×3 Coupler
摘要
Abstract
The 3×3 coupler-based Michelson interference demodulation system was established to achieve a stable demodulation of distributed feedback optical fiber laser sensor (DFB FL) in a wide dynamic range.The symmetric demodulation algorithm (NPS) and arctangent demodulation algorithm used in this system were in-depth researched.Firstly,the theory of the 3×3 coupler-based demodulation algorithm and calibration method used in asymmetry coupler were presented.Secondly,the selection of minimum unbalanced interferometer path length,as well as the relation of system noise and frequency noise of laser were analyzed.Next,the amplitude of the maximum demodulated signal of NPS and the arctangent algorithm were compared.At last,the effect of differentiator on the dynamic range of NPS method was analyzed.The experiment results show that the dynamic range of NPS method is wider than that of arctangent algorithm,and a bad amplitude-frequency characteristic of differentiator will narrow the dynamic range of demodulation.The dynamic range of NPS algorithm and arctangent algorithm reaches to 96 dB and 91 dB respectively when the sampling frequency is 125 kHz,signal frequency is 1 kHz,and interferometer`s unbalanced length is 100 m.By applying calibration before demodulation,the 3×3 coupler-based demodulation methods may produce a large dynamic range,which can achieve a stable demodulation and meet the requirements of engineering application.关键词
分布反馈式光纤激光传感器/3×3耦合器/被动零差解调Key words
distributed feedback optical fiber laser(DFB FL) sensor/3×3 coupler/passive homodyne demodulation分类
信息技术与安全科学引用本文复制引用
毛欣,黄俊斌,顾宏灿..采用3×3耦合器的分布反馈式光纤激光传感器解调技术[J].发光学报,2017,38(3):395-401,7.基金项目
粤港关键领域重点突破项目(2004A10403021) （2004A10403021）
广东省攻关计划(2006A10401006)资助项目 Supported by Key Breakthrough Projects of Key Areas of Guangdong and Hong Kong(2004A10403021) （2006A10401006）
Guangdong Provincial Research Program(2006A10401006) （2006A10401006）
