基于微纳光纤的长周期光栅及温度传感系统的设计与制备

Design and fabrication of long period fiber gratings in microfiber and the temperature sensing system

为了获得高精度的温度传感系统,提出并验证了一种基于长周期光栅(LPG)温度传感系统。首先利用普通单模光纤(MSF)拉制了微纳光纤,拉制的微纳光纤直径约为6.2μm;其次,利用CO2脉冲激光器在拉制的微纳光纤上制作了微纳LPG,光栅的周期为100μm;利用获得的微纳LPG结合马赫-曾德干涉仪(MZI)设计了温度传感系统,在系统中利用声光调制器(AOM)作为移频调制器,获得了200 MHz的微波信号,且随LPG测量温度的增加,微波信号的相对强度逐渐增加,其斜率约为0.46(a.u)/℃。在30min的时间间隔内,测量了信号强度的稳定性,强度变化约为0.5dB,表明系统展现了较高的稳定性。

In order to obtain high-precision temperature sensing system,a fiber grating temperature sensing system based on a long period grating （LPG） is proposed and experimentally demonstrated. Firstly, a microfiber with a diameter of 6.2 μm is obtained by drawing the conventional single mode fibers. Secondly, a long period grating （LPG） is obtained in the microfiber by using CO2 laser, and the grating period is about 100μm A temperature sensing system with the Mach-Zehnder interferometer （MZI） and LPG is designed, a acousto-optic modulator （AOM） is used to shift the frequency in the system, and a 200 MHz microwave signal is obtained. With the increase of measurement temperature, relative intensity of the microwave signal is gradually increased,and the slope is about 0. 46 （a. u）/℃. In 30 rain,the stability of the microwave signal is measured,and the fluctuation in the intensity is about 0.5 dB, and the experimental results show that the system has high stability.