Channel and frequency extending method and system for FBG (fiber bragg grating) demodulation instrument

Abstract

The invention discloses a channel and frequency extending method and system for an FBG (fiber bragg grating) demodulation instrument, and the system comprises a light source; a piezoelectric ceramic tunable wavelength filter which is used for converting the light from the light source into sweep frequency light in a time domain; an optical grid generator which is used for selecting the passing sweep frequency light and outputting a standard spectrum signal; two to-be-measured optical grating channels which are connected with different optical gratings and output different to-be-measured spectrum signals; a photoelectric conversion module which is used for converting the standard spectrum signal and the to-be-measured spectrum signals into electric signals, and controlling output signals according to different extending modes, which comprise a channel extending mode and a frequency extending mode; a data collection module which is used for collecting the signals outputted by the photoelectric conversion module; and a signal demodulation module which is used for carrying out the grouping, correction, demodulation and outputting of the signals collected by the data collection module.

Description

technical field [0001] The invention belongs to the field of optical fiber grating sensing, and can provide a frequency and channel expansion method for a piezoelectric ceramic type optical fiber grating demodulator. Double the demodulation frequency or the number of working channels without adding any components. Background technique [0002] The piezoelectric ceramic tunable wavelength filter uses the Fabry-Perot structure to achieve variable wavelength output by changing the distance between the two mirrors through piezoelectric ceramics; A good triangular wave voltage drives piezoelectric ceramics. The rising stage of the triangular wave corresponds to the process of changing the length of the Fabry-Perot cavity, and the falling stage of the triangular wave corresponds to the process of changing the length of the Fabry-Perot cavity. Such as figure 1 shown. [0003] In the past fiber grating demodulator, because the hysteresis effect exhibited by the piezoelectric cera...

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Problems solved by technology

[0004] The technical problem to be solved by the present invention is to provide a method to increase the working frequency of the demodulator or the number of working channels of the demodulator without adding any devices to the defect that the data in the falling edge cannot be effectively used in the prior art. Expanding method and system of doubled fiber grating demodulator

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