Dual-wavelength temperature measurement method based on long-period fiber bragg grating

Abstract

The invention relates to the technical field of optical fiber temperature measurement, in particular to a dual-wavelength temperature measurement method based on a long-period fiber bragg grating, which comprises the following steps of acquiring an original optical signal emitted by the long-period fiber bragg grating, carrying out light splitting processing on the original optical signal to obtain two corresponding beams of measurement optical signals, filtering the two beams of measurement light signals respectively to obtain two corresponding beams of filtered transmission light, and then collecting two transmission light intensity values corresponding to the two beams of filtered transmission light respectively, and calculating to obtain a corresponding temperature value according to the two transmitted light intensity values and a set calculation model. Compared with the prior art, the dual-wavelength temperature measurement method based on the long-period fiber bragg grating hasthe advantages that the temperature is measured by using the intensity value instead of wavelength change, the interference of the intensity fluctuation of the incident light source can be eliminated,the measurement cost during temperature measurement can be reduced, and the measurement precision during temperature measurement is improved.

Description

technical field [0001] The invention relates to the technical field of optical fiber temperature measurement, in particular to a dual-wavelength temperature measurement method based on a long-period fiber grating. Background technique [0002] Fiber Bragg grating sensor is a kind of fiber optic sensor. The sensing process based on fiber Bragg grating is to obtain sensing information through the modulation of the wavelength and intensity of fiber Bragg grating by external physical parameters. According to the length of the fiber grating period, fiber gratings with a period of less than 1 μm are usually called short-period fiber gratings, also known as fiber Bragg gratings or reflection gratings; while fiber gratings with a period of tens to hundreds of microns are called long-period fibers. Grating, also known as transmission grating. Compared with ordinary fiber Bragg gratings (that is, short-period fiber gratings), long-period fiber gratings have higher temperature and str...

AI Technical Summary

Problems solved by technology

For this reason, the applicant thought of changing the existing temperature measurement method of wavelength modulation, and reflected the change of wavelength on the change of light intensity, and then designed a temperature measurement method based on light intensity change, so as to avoid the The problem of high cost of measurement

However, the measurement method of light intensity change has high requirements on the stability of the incident light source (laser light source is required, and its cost is also high), because the fluctuation of the intensity of the incident light source will bring large measurement errors, which in turn makes the temperature measurement The measurement accuracy is low

Images