Recent Progress in Optical Fiber Sensors Based on Brillouin Scattering at University of Ottawa

分布式的传感器被证明是一个强大的工具为民用结构并且监视的材料过程。在纤维散布的 Brillouin 能被用作点传感器或为分布式的传感器为点传感器或脉搏长度在厘米(Brillouin 栅栏长度) 上为温度，紧张， birefringence 和颤动的测量散布了传感器。有 20 厘米的空间分辨率的同时的紧张和温度测量与温度精确性和 0.4 的紧张精确性用 Brillouin 栅栏技术在熊猫纤维被表明吗？？

The distributed sensor is proven to be a powerful tool for civil structural and material process monitoring. Brillouin scattering in fiber can be used as point sensors or distributed sensors for measurement of temperature, strain, birefringence and vibration over centimeters （Brillouin grating length） for point sensor or the pulse length for the distributed sensor. Simultaneous strain and temperature measurement with a spatial resolution of 20 cm is demonstrated in a Panda fiber using Brillouin grating technique with the temperature accuracy and strain accuracy of 0.4 ℃ and 9 με. This technique can also be used for distributed birefringence measurement. For Brillouin optical time domain analysis （BOTDA）, we have developed a new technique to measure differential Brillouin gain instead of Brillouin gain itself. This technique allows high precision temperature and strain measurement over long sensing length with sub-meter spatial resolution： 50-cm spatial resolution for 50-km length, using return-to-zero coded optical pulses of BOTDA with the temperature resolution of 0.7 ℃, which is equivalent to strain accuracy of 12 με. For over 50-km sensing length, we proposed and demonstrated frequency-division-multiplexing （FDM） and time-division-multiplexing （TDM） based BOTDA technique for 75-km and 100-km sensing length without inline amplification within the sensing length. The spatial resolution of 2m （100km） and Brillouin frequency shift accuracy of 1.5 MHz have been obtained for TDM based BOTDA and 1-m resolution （75 km） with Brillouin frequency shift accuracy of 1 MHz using FDM based BOTDA. The civil structural health monitoring with BOTDA technique has been demonstrated.