Automatic calibration circuit and calibration method of f-p filter of fiber grating demodulator

Abstract

The invention discloses an automatic calibration circuit of an F-P filter of an optical fiber grating demodulator. The CPU controls the output voltage of the first DA converter to reach the starting point voltage; the output voltage of the second DA converter is used as the output voltage of the third DA converter. Reference voltage, by adjusting the output voltage of the second DA converter, the output voltage range of the third DA converter can be adjusted. The voltage adder superimposes the starting voltage and the scanning voltage, and then reverses the phase through the voltage inverter to drive the F‑P filter. The invention also discloses an automatic calibration method for the F-P filter of a fiber grating demodulator. During operation, after each scanning measurement, the center voltage V3 of the first wave peak of the etalon and the center voltage of the last wave peak are calculated. Voltage V4, V1~V2 of the output voltage Vo range of the control voltage adder is V3‑1.5V~V4+1.5V. The invention can automatically determine the voltage scanning range of the F-P filter, saving time and effort.

Description

technical field [0001] The invention relates to an automatic calibration circuit for an F-P filter of an optical fiber grating demodulator, and also relates to an automatic calibration method for an F-P filter of an optical fiber grating demodulator. Background technique [0002] As a new generation of sensors, fiber optic sensors can measure many physical quantities, chemical quantities and biomass with high resolution, and can realize the measurement of on-site non-electrical measurements, which essentially solves the problem of flammability and flammability that traditional electrical sensors are difficult to get involved in. It can detect the safety measurement of explosive and strong electromagnetic field places; it can conveniently, accurately and effectively detect the relevant physical quantities, chemical quantities and biomass in various environments, especially in various harsh environments. In addition, the optical fiber has a large information capacity, and mult...

AI Technical Summary

Problems solved by technology

[0006] (1) The scanning voltage needs to be adjusted manually

[0007] Since the scanning voltage range of each F-P filter corresponding to the wavelength between 1525 and 1565nm is not fixed, the driving voltage range of the F-P filter is currently adjusted manually, which is extremely time-consuming and laborious.

[0008] (2) F-P filter is greatly affected by temperature

[0009] At different temperatures, the scanning voltage range of each F-P filter corresponding to the wavelength between 1525 and 1565nm is not fixed. It is necessary to determine the scanning voltage range of the F-P filter at high and low temperature respectively, and take the scanning voltage at high and low temperature The union of the range, so as to meet the normal measurement at high temperature, which will greatly reduce the resolution of the measurement, and the whole calibration process consumes a lot of manpower

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