带光纤环的分布式光纤拉曼温度系统

Distributed optical fiber Raman temperature system with an optical fiber ring

为了抑制分布式光纤拉曼温度系统的温漂和瑞利散射光窜扰反斯托克斯散射光,在传感光纤前端盲区后放置光纤取样环,用瑞利散射光解调反斯托克斯散射光及用光纤取样环的温度计算光纤线上其它点的温度,提高了系统的测温精度和稳定性。采用功率100 mW,波长1.55μm,脉宽10 ns脉冲激光器和15 dB前置光纤放大器,100M14bitA/D转换卡及DSP作数字平均构建光纤拉曼温度系统的实验,实现了测温误差在±0.03℃内。

For restraining the temperature excursion accumulation Rayleigh back-scattering, an optical fiber sampling ring was set after an and the anti-Stokes back-scattering intermingling with the inswept death section of the sensing optical fiber. The anti-Stokes back-scattering was demodulated by Rayleigh back-scattering and the fiber＇s temperature was calculated by the sampling ring, which advanced the temperature precision and stability of the system. A 10 ns, 100 mW, 1.55 μm pulse laser, a 15 dB gain of EDFA, two high sensitive and low noise APD, twol00M14bitA/D and two DSP chips using for 2^12-2^13 digital average form the experimental system. The spatial resolution of 1 m and temperature resolution of 0. 03 ℃ were achieved using these techniques.