Fiber grating demodulator calibration transfer member and calibration method

Abstract

The invention discloses a fiber grating demodulator calibration transfer member and a calibration method. The fiber grating demodulator calibration transfer member comprises a 2*2 coupler, an isolator, an F-P etalon, an annular device with three ports and a reflective load. One end of the coupler is connected with one end of the F-P etalon through the isolator. The other end of the F-P etalon is connected with one port of the annular device. The other two ports of the annular device are respectively connected with the reflective load and the other end of the coupler. The F-P etalon is adopted as a core device to make the calibration transfer member. A series of calibration wavelength points can be provided. The calibration data of a fiber grating demodulator can be more reliable. Meanwhile, the F-P etalon has relatively good temperature stability. The requirements for temperature control can be lowered. Good environment adaptability is achieved. Furthermore, by adopting the 2*2 coupler, the calibration transfer member is enabled to have two output ports. Calibration demands of single-channel and multi-channel fiber grating demodulators can be satisfied at the same time.

Description

Technical field [0001] The invention relates to a fiber grating demodulator calibration transfer 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 warning, petrochemical, aerospace, civil 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 function 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 accurate measurement capability of changes in external physical quantities, and the dynamic range determines the number of fiber grating sensors that can be connected in the demodulation system. [0003] At present, there is ...

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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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