光纤外差干涉位移传感器性能的提高

Improving the properties of the optical-fiber heterodyne-interference displacement sensor

利用半导体激光器 (LD)、光隔离器、光纤定向耦合器、自聚焦透镜等组成双路光纤斐索型干涉仪。采用三角波电流调制 ,上、下边沿拍频信号差动鉴相的方法 ,提高了测量灵敏度和位移响应速度 ,增大了测量范围 ;利用辅助干涉仪检测系统的相位漂移 ,并对LD发光波长进行反馈控制 ,提高了系统的稳定性 ,实现了大测量范围、高分辨率、高精度位移测量。

The displacement sensor was realized on basis of a double channel optical fiber Fizeau type interferometer, which consists of laser diode(LD),optical isolator,optical fiber directional coupler,self focusing lens and etc. By advantages of triangular edge beat signals, the properties of the system were improved with higher measurement sensitivity, faster respond to displacement and wider measurement scope. In addition, a complementary interferometer was used to detect the phase excursion of the system and control the light wavelength of the LD by feedback using close circuit, which resulted in enhanced stability and further improved properties of the system, such as large measurement scope, high resolution and high accuracy.