Cavity length demodulation algorithm of short cavity optical fiber fabry-perot sensor

Abstract

The invention discloses a cavity length demodulation algorithm of a short cavity optical fiber fabry-perot sensor, and belongs to the technical field f optical fiber sensing. The cavity length demodulation algorithm of the short cavity optical fiber fabry-perot sensor is characterized by comprising the following steps: irradiating the short cavity optical fiber fabry-perot sensor by broadband light emitted by a white light source, acquiring reflection spectrum of the short cavity optical fiber fabry-perot sensor, moving the original reflection spectrum signal by a certain distance, which is less than the cycle length of the reflection spectrum signal, in the x-coordinate direction of a power spectrum density map to obtain an additional reflection spectrum signal, evaluating phase difference of the original spectrum signal and the additional spectrum signal by utilizing an ellipse fitting method, and obtaining an actual absolute cavity length value according to a fabry-perot cavity length calculation formula. By the cavity length demodulation algorithm of the short cavity optical fiber fabry-perot sensor, the problem about cavity length demodulation when the short cavity optical fiber fabry-perot sensor demodulation system acquires incomplete spectrum is solved, and the requirement on the light source spectrum range by the system is reduced.

Description

technical field [0001] The invention belongs to the technical field of optical fiber sensing, and in particular relates to a cavity length demodulation algorithm of a short-cavity optical fiber F-P sensor. Background technique [0002] Fiber optic Fab sensor is an important type of phase fiber optic sensor. This kind of fiber optic sensor is small in size and easy to manufacture. Compared with similar electronic sensors, it has small size, light weight, high sensitivity, and is not affected by electromagnetic interference. Advantages such as remote sensing. Due to the various options of Fab cavity materials, fiber optic sensors can be used in harsh industrial and military environments such as high temperature, high pressure, strong chemical corrosion and strong electromagnetic interference, such as the measurement of pressure and temperature in deep oil wells, bridges, large The health monitoring of dams, the acoustic detection of nuclear explosion experiment sites, the hea...

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Problems solved by technology

[0006] The purpose of the present invention is to provide a cavity length demodulation algorithm of a short-cavity optical fiber F-P sensor, so as to overcome the problem that the existing technology cannot use the spectrum method to demodulate the incomplete spectrum to obtain the cavity length and the cavity length demodulation accuracy is low problem, and at the same time solve the problem that requires a wide bandwidth of the light source

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