Dynamic phase demodulation and calibration method for high-reflectance optical fiber F-P chamber hydrophone

Abstract

The invention provides a high-reflectance optical fiber F-P chamber transient speed variation phase high-speed linear demodulation method which comprises the following steps: measuring a relationship curve between high-reflectance multi-light optical fiber F-P chamber reversed detection interference output and scanning wavelength by using a wavelength scanning method; acquiring the primary physical chamber length of the F-P chamber; selecting central wavelength of three laser light sources according to the relationship curve between the F-P chamber reversed detection interference output and the scanning wavelength; exciting the F-P chamber through the three laser light sources; adjusting the output power of each laser light source; designing and manufacturing a static pressure experimental clamp with a laser wave pressure senor of the F-P chamber, making a static pressure loading experiment, and drawing corresponding relationship curves between the interference output and external static pressure under the excitation of the laser light sources; making a static characteristic calibration experiment by using a demodulator so as to obtain interference output variation phase of the F-P chamber and a linear relationship curve between the external static pressure and the interference output, and furthermore achieve linear calibration on the interference output variation phase of the F-P chamber.

Description

technical field [0001] The invention relates to the technical field of dynamic measurement of underwater shock wave pressure based on an optical fiber F-P cavity, especially based on a high-reflectivity multi-beam interference optical fiber F-P cavity as a core device, and the field of dynamic calibration of an ultra-miniature underwater shock wave pressure sensor. Background technique [0002] Optical fiber Fabry-Perot (F-P) cavity is an extremely important branch of the fiber optic sensor family. Its own volume is small, and the cavity length is generally micron (5um-50um). The potential high-frequency response characteristics are very suitable for dynamic physical quantities. Measurement. The all-silica fiber Fresnel (Fizeau) cavity is also a fiber optic F-P cavity, and the other reflection surface of the F-P cavity is a flat pressure-sensitive thin plate, coupled with its small size and high-frequency response characteristics, it is very suitable for transient speed The...

AI Technical Summary

Problems solved by technology

[0007] The technical problem to be solved by the present invention is to provide a high-reflectivity optical fiber F-P cavity transient fast-changing phase high-speed linear demodulation method, which can solve the problem that the transient fast-changing phase of the multi-beam interference fiber F-P cavity cannot be detected linearly at high speed

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