Measurement of Refractive Index with a PM-LPG Based Sagnac Loop Sensor
KANG Juan1,2, DONG Xin-yong1, ZHAO Chun-liu1, ZHANG Zai-xuan1, JIN Shang-zhong2
1. Institute of Optoelectronic Technology, China Jiliang University, Hangzhou 310018, China 2. School of Optical-Electrical and Computer Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China
Abstract：By inscribing a long-period fiber grating (LPG) on a polarization-maintaining fiber (PMF), a fiber Sagnac loop sensor for simultaneous measurement of refractive index and temperature has been proposed and demonstrated. The LPG was fabricated on the PMF by using a CO2 laser, and then inserted into a fiber loop formed by using a normal single-mode fiber coupler. One of the transmission minimum of the Sagnac loop sensor was measured, whose wavelength varied with temperature and the intensity changed with refractive index. Temperature sensitivity of -0.654 nm·℃-1 and refractive sensitivity of 49.9 dB·RIU-1 have been achieved. The sensor system shows advantages of small size and low cost, and owns a good application prospect.
Key words：Fiber Sagnac loop;Polarization-maintaining fiber;Long-period fiber grating;Refractive index sensor
康 娟1,2，董新永1，赵春柳1，张在宣1，金尚忠2 . 基于长周期光纤光栅嵌入型Sagnac环光谱的折射率测量 [J]. 光谱学与光谱分析, 2011, 31(04): 902-905.
KANG Juan1,2, DONG Xin-yong1, ZHAO Chun-liu1, ZHANG Zai-xuan1, JIN Shang-zhong2 . Measurement of Refractive Index with a PM-LPG Based Sagnac Loop Sensor. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2011, 31(04): 902-905.
