近年来光纤光栅在传感领域中的应用研究日益得到关注,其中光纤光栅波长解调是光纤光栅传感器得到应用推广的关键之一。针对大型建筑结构监测应用领域,研制了一种便携式光纤Bragg光栅波长解调仪。解调仪基于无源比例解调原理,以熔融拉锥器件作为线性滤波器,采用锁相放大技术提取微弱信号,并利用单片机控制光纤Bragg光栅波长信息的采集、显示以及存储。解调仪结构简单、成本低,可实现大量程波长测量。实验表明,该光纤光栅解调仪解调范围达15nm,波长测量精度为12.4pm。
The application research of fiber Bragg grating in sense field attracts more and more attention in recent years, and its wavelength demodulation is one of the most important technologies which extend the application of fiber Bragg grating sensor. A portable fiber Bragg grating wavelength demodulation instrument was designed for the application field of large building structure inspection. The demodulation instrument is based on passive proportion demodulation method, which uses a fused taper component as the linear filter, adopts lock-in amplifier technology to detect the weak signal, and makes use of a single chip microcomputer to control the acquisition, display and storage of the wavelength data of fiber Bragg grating. The demodulation instrument features simple structure, low cost, and can carry out large range wavelength measurement. The experiments show that its wavelength demodulation range is 15 nm and the measurement accuracy is 12.4 pm.