Department of Electric and Electronic Engineering, Public University of Navarra, 31006 Pamplona, Spain.
Sensors (Basel). 2011;11(9):8711-20. doi: 10.3390/s110908711. Epub 2011 Sep 8.
We propose and demonstrate two ultra-long range fiber Bragg grating (FBG) sensor interrogation systems. In the first approach four FBGs are located 200 km from the monitoring station and a signal to noise ratio of 20 dB is obtained. The second improved version is able to detect the four multiplexed FBGs placed 250 km away, offering a signal to noise ratio of 6-8 dB. Consequently, this last system represents the longest range FBG sensor system reported so far that includes fiber sensor multiplexing capability. Both simple systems are based on a wavelength swept laser to scan the reflection spectra of the FBGs, and they are composed by two identical-lengths optical paths: the first one intended to launch the amplified laser signal by means of Raman amplification and the other one is employed to guide the reflection signal to the reception system.
我们提出并演示了两种超远距离光纤布拉格光栅（FBG）传感器检测系统。在第一种方法中，四个 FBG 位于距离监测站 200 公里的位置，获得了 20dB 的信噪比。第二个改进版本能够检测到放置在 250 公里外的四个复用 FBG，提供 6-8dB 的信噪比。因此，最后一个系统代表了迄今为止报道的最长距离 FBG 传感器系统，它包括光纤传感器复用能力。这两个简单的系统都基于波长扫描激光来扫描 FBG 的反射光谱，并且它们由两个相同长度的光路组成：第一个用于通过拉曼放大发射放大后的激光信号，另一个用于将反射信号引导到接收系统。
