基于阵列波导光纤温度特性的分布式光纤布喇格光栅解调法

A New Demodulated System of Distributed FBG Based on Temperature Characteristics of AWG

设计了一种使用阵列波导光栅对分布式光纤布喇格光栅中心波长较大范围变化的解调方法.根据阵列波导光栅各通道的中心波长可随温度变化而改变的特性,通过控制软件循环地在几分钟内使加在阵列波导光栅的芯片温度从30℃线性增加到90℃,同时用微机高速采集各通道的数据并分别找出各通道数据的最大值时刻所对应的阵列波导光栅芯片温度,从而根据其波长-温度关系在微机上报告此时各光纤布喇格光栅的中心波长.实验结果表明,系统有效地解决了分布式解调的问题,微机以小于10min的周期报告出每通道0.6nm范围变化的光纤布喇格光栅中心波长(共40个通道),测量相对误差小于2%.

A set of using arrayed waveguide grating(AWG) for distributed fiber Bragg grating(FBG) wide variation of center wavelength demodulation method is presented.According to the characteristics that AWG center wavelength of each channel can change with the chip′s temperature changes,a voltage control circuit was designed,and the chip′s temperature can vary from 30℃ to 90℃ periodically,several minutes per period.Simultaneously,the data of the channels of AWG can be collected in high speed by a computer.Then the chip′s temperature can be found responding to the maximum of each channel.Finally,the computer can report central wavelength of FBG according the relationship of wavelength and temperature.The experiment demodulating system was established.The experiment results prove that the system can effectively resolve the problem of measurement range.The system can report the central wavelength of FGB in 0.6 nm each channel(40 channels in total) in less than 10 minutes,but also measurement error is less than 2 percent.