Optical frequency domain reflectometer with optical wave frequency shift modulation

Abstract

The invention discloses an optical frequency domain reflectometer with optical wave frequency shift modulation, which comprises a narrow linewidth scanning laser, a first optical fiber coupler, an optical circulator, a to-be-measured optical fiber, an optical wave frequency shifter, a second optical fiber coupler, a first polarization beam splitter, a second polarization beam splitter, a first balanced photodetector, a second balanced photodetector, a third optical fiber coupler, a first Faraday rotating mirror, a second Faraday rotating mirror, a reference optical fiber interferometer, a photodetector and a signal acquisition and processing unit. Through frequency shift modulation on measurement light and reference light, interference signals produced by superposition of scattering signal light of the to-be-measured optical fiber which is symmetrical about zero delay and local oscillation light are separated on the spectrum. According to the optical frequency domain reflectometer with optical wave frequency shift modulation, mutual interference among the interference signals of the to-be-measured optical fiber scattering signal light which is symmetrical about zero delay can be suppressed, measurement of the scattering signal light which is symmetrical about zero delay can be realized, and the maximum optical fiber measurement length can be improved.

Description

technical field [0001] The invention relates to an optical frequency domain reflectometer, in particular to an optical frequency domain reflectometer with light wave frequency shift modulation. Background technique [0002] Optical frequency domain reflectometer is an important means of optical fiber sensing measurement and optical fiber device measurement; through optical frequency domain reflectometer to measure the backward Rayleigh scattering along the optical fiber and the backward reflection of the fiber grating, the temperature, strain, vibration, etc. of the optical fiber can be realized. Distributed measurement or multi-point measurement; through optical frequency domain reflectometer to measure the Rayleigh scattering of optical fiber and the back reflection of optical device, it can realize the measurement of various parameters such as loss, dispersion and polarization of optical fiber and optical device . [0003] For optical fiber sensing measurement applicatio...

AI Technical Summary

Problems solved by technology

[0008] The technical problem solved by the present invention is: for the existing optical frequency domain reflectometer, there is a problem of mutual interference between the interference signals of scattered signal light symmetrical to zero time delay; an optical frequency reflectometer with optical frequency shift modulation is proposed, through Optical wave frequency shift modulation suppresses mutual interference between interference signals of scattered signal light with respect to zero-delay symmetry, reduces the difficulty of optical path adjustment, and increases the maximum measurement fiber length at the same time

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