阵列波导光栅解调的光纤光栅振动频率检测技术

提出一种基于阵列波导光栅相对强度解调的光纤光栅振动频率检测方法．振动引起的光纤光栅布拉格波长漂移由阵列波导光栅中相对应的2个相邻输出通道的相对光强变化进行解调，利用数据采集卡和虚拟仪器软件对其光电转换信号进行数据采集和频谱分析可得到振动频率．实验结果表明，该方法测出的振动频率与振动源设置的频率相吻合，且可有效消除由光源不稳定、微弯损耗等引起的误差影响，能够更方便实现准分布式光纤光栅振动传感系统的快速、准确测量．

A NOVEL DETECTION OF THE FREQUENCY OF THE FIBER BRAGG GRATING VIBRATION BASED ON ARRAYED WAVEGUIDE GRATING DEMULTIPLEXING

A novel detection of the frequency of the Fiber Bragg Grating vibration based on the relative intensity demodulating of an arrayed waveguide grating (AWG) is presented. The shift of the Bragg wavelength of the FBG sensors caused by the vibration can be demodulated by the relative intensity change of the corresponding pair of the AWG's two-adjacent-output-channels. Their photoelectric signal is acquired by the data acquisition card, and then a frequency analysis is carried out to get the frequency of the vibration. The experimental results are in line with the set frequencies of the vibration source. With this technique, errors caused by the light source fluctuation and micro-bend losses can be eliminated, and it will be more convenient to realize the frequency detection of the FBG distributed sensing system.