用于FBG解调的光纤F-P可调滤波器温漂抑制

Inhibiting Temperature Drift of Fiber Fabry-Perot Tunable Filter for Interrogating Fiber Bragg Grating Sensor

光纤法布里-珀罗可调滤波器(FFP-TF)是组成光纤布拉格光栅(FBG)传感器解调系统的核心器件之一,其稳定性对解调精度的提高至关重要,而温度漂移是影响其稳定性的关键因素之一。针对实际应用中遇到的FFP-TF温漂问题,分析了温漂产生的原因和滤波器在给定驱动电压下中心波长随温度的变化关系,提出了一种温度控制与参考光栅相结合的复合温漂抑制方法,实验分析了相应温控装置的性能并将其成功用于FBG压力传感器的信号解调系统中。结果表明,基于该温漂抑制方法的FFP-TF解调方案,可广泛应用于FBG传感器系统中。

The fiber Fabry-Perot tunable filter （FFP-TF） is the core of a fiber Bragg grating （FBG） interrogation system, whose stability is a key factor for improving the interrogation accuracy but is affected by temperature drift. We analyze the causes of the temperature drift and the variation of the central wavelength of the tunable filter under a given driving voltage with temperature and then propose a compound temperature drift inhibition method that com hines temperature control with a reference FBG. We carried out experiments on the performance of the temperature control device and apply our compound temperature drift inhibition method to the signal interrogation system of an FBG pressure sensor. The experimental results, given in Figs. 8 and 9, and their analysis show preliminarily that the interrogation accuracy of the FBG pressure sensor is better than 0.5 % F. S, thus enhancing the accuracy of the FBG interrogation system greatly. Therefore, the FFP-TF demodulation scheme based on the compound temperature drift inhibition method can be applied to a FBG pressure sensor.