光开关在分布式光纤温度传感系统的应用研究

Application research of optical switch in distributed optical fiber temperature sensor system

分析了决定分布式光纤温度传感器系统传感距离的因素,提出了使用光开关扩展系统的传感长度。设计了多模1×2棱镜光开关的单片机驱动接口,计算机软件通过RS232串行接口发出指令控制光开关的切换。测试结果表明,嵌入了1×2光开关可使系统传感光纤长度延伸为原来的2倍。

The working principle,engineering application and development trends of distributed optical fiber temperature sensor are introduced briefly.Factors that determine the length of sensing optical fiber are discussed in particularly.In distributed optical fiber temperature sensor system,the length of sensing optical fiber is determined by power of laser,loss coefficient of optical fiber and signal to noise ratio（SNR） of the system.A method to extend the sensing length of the system is proposed by using optical switch.A driver interface using single chip processor for a multi-mode prism 1×2 optical switch is designed.Computer controls optical switch through the RS232 serial interface.Test results show that the system can be extended to double sensing length by embedding 1×2 optical switch.