A high-precision and high-speed fiber grating sensor wavelength demodulation method

Abstract

The invention discloses a demodulation method for the wave length of a high-precision high-speed fiber Bragg grating sensor. A high-speed triangular wave voltage signal is adopted for driving a tunable F-P light source, and through triangular wave rising edge and falling edge driving signals in the same period, the problem is solved that since an optical spectrum signal and an etalon spectrum lineof the sensor are not synchronized, the demodulation wave length is out of line. By adopting the etalon spectrum line, the tunable F-P light source is subdivided, multiple optical spectrums are obtained and used as reference, the demodulation wave length fluctuation caused by characteristics such as delaying, creep and nonlinearity of piezoelectric ceramics of a tunable filter in the tunable F-Plight source can be effectively restrained, the demodulation precision of the wave length of the fiber Bragg grating sensor is effectively improved, and state information such as strain, temperature and acceleration of key structures of a spacecraft, an airplane and the like is collected.

Description

technical field [0001] The invention belongs to the technical field of fiber grating sensing, and in particular relates to a wavelength demodulation method of a high-precision and high-speed fiber grating sensor. Background technique [0002] The optical fiber grating sensing system is based on the optical signal as the carrier. The optical fiber grating sensor converts information such as temperature, strain and acceleration into the change of the wavelength of the optical signal, and uses a demodulation device to demodulate the wavelength of the optical signal. The system has small size and light weight. , Strong anti-electromagnetic interference ability and strong corrosion resistance, etc., can be applied in harsh environments such as strong electromagnetic interference, thermal vacuum or radiation. [0003] The tunable F-P filtering method is a commonly used fiber grating sensing demodulation method. Through the key components such as tunable F-P light source, etalon an...

AI Technical Summary

Problems solved by technology

[0004] In view of this, the purpose of the present invention is to provide a high-precision high-speed fiber grating sensor wavelength demodulation method, to solve the problem that the sensor spectral signal and the etalon spectral line are not synchronized to cause the demodulation wavelength shift, and to suppress the F-P light source internal adjustable The problem of demodulation wavelength fluctuation caused by the piezoelectric ceramics of the filter due to characteristics such as hysteresis, creep and nonlinearity

Images