Calibration transfer part and calibration method of fiber grating demodulator

Abstract

The invention discloses a fiber grating demodulator calibration transmission part and a calibration method. The calibration transfer part of the fiber grating demodulator includes a 2×2 coupler, an isolator, an F-P etalon, a circulator with three ports and a reflective load; wherein, one end of the coupler is connected to the F-P standard through the isolator The other end of the F-P etalon is connected to one port of the circulator; the other two ports of the circulator are respectively connected to the reflective load and the other end of the coupler. The present invention adopts the F-P etalon as the core device to make the calibration transfer part, which can provide a series of calibration wavelength points, so that the calibration data of the fiber grating demodulator is more reliable; and the temperature stability of the F-P etalon is better, The requirements for temperature control can be reduced, and the environment adaptability is good; in addition, the present invention adopts a 2×2 coupler so that the calibration transmission part has two output ports, which can simultaneously meet the calibration requirements of single-channel and multi-channel fiber grating demodulators.

Description

technical field [0001] The invention relates to a fiber grating demodulator calibration transmission part and a fiber grating demodulator calibration method. Background technique [0002] Fiber Bragg grating demodulator has a very wide range of applications in the fields of fire early warning, petrochemical, aerospace, civil and construction health monitoring, etc. It can realize long-distance measurement and monitoring, and has the characteristics of wide measurement range, high precision and high resolution. Its role is to demodulate and measure the distributed network composed of fiber grating sensors. The main parameters that characterize its performance are the central wavelength and dynamic range. The demodulation accuracy of the central wavelength determines the ability to accurately measure changes in external physical quantities, and the dynamic range determines the number of FBG sensors that can be connected to the demodulation system. [0003] At present, there i...

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Problems solved by technology

[0003] At present, there is no unified standard for the calibration of fiber grating demodulators. The calibration of the center wavelength is usually carried out by using a standard fiber grating. The method is simple and feasible, but the fiber grating is written by a phase mask, and only a few For fixed wavelength points, compared with the working wavelength range of the demodulator, there are fewer calibration wavelength points, and the fiber grating is very sensitive to external temperature changes. In order to keep the central wavelength value stable, the requirements for temperature control are high. Poor adaptability

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