Inhibiting temperature drift of Fiber Fabry-Perot tunable filter for interrogating fiber Bragg grating sensor

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 combines 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.