Optical frequency domain reflectometer device based on Fourier domain mode locking and measuring method

Abstract

The invention provides an optical frequency domain reflectometer device based on Fourier domain mode locking and a measuring method, and belongs to the field of optical frequency domain reflectometers. The problems that an existing optical frequency domain reflectometer device and method are limited by a tuning light source, the tuning speed is low, the tuning range is small, and polarization sensitivity exists are solved. The device is characterized in that a Fourier domain mode-locked tuning light source sequentially passes through a second optical isolator and a second polarization-maintaining optical fiber coupler and then is respectively connected with an auxiliary interferometer, a double-shaft working polarization splitting prism and a polarization-maintaining optical amplifier, and the auxiliary interferometer is connected with a signal processing module; the biaxial working polarization splitting prism is respectively connected with the fourth polarization-maintaining optical fiber coupler and the fifth polarization-maintaining optical fiber coupler, and the polarization-maintaining optical amplifier and the second delay line are respectively connected with the fourth polarization-maintaining optical fiber coupler and the fifth polarization-maintaining optical fiber coupler after sequentially passing through the polarization-maintaining circulator and the uniaxial working polarization splitting prism. The optical frequency domain reflectometer is mainly used for optical frequency domain reflectometers.

Description

technical field [0001] The invention belongs to the field of optical frequency domain reflectometers, in particular to an optical frequency domain reflectometer device and measurement method based on Fourier domain mode locking. Background technique [0002] In recent years, with the continuous deepening of the role of intelligent flexible structures in the fields of aerospace, smart cities, and smart medical care, how to perform structural health monitoring and adaptive control on intelligent flexible structures has become one of the problems to be solved urgently. In this respect, fiber optic sensors with the characteristics of flexibility, light weight, and electromagnetic shielding have good compatibility with intelligent flexible structures; in addition, optical fibers themselves can be used as a good medium for optical signal transmission, which enables fiber optic sensors to control Distributed measurement of stress / strain conditions in smart flexible structures. [...

AI Technical Summary

Problems solved by technology

[0004] However, the external cavity laser tuning technology ECL, the vertical cavity surface emitting laser tuning technology VCSEL, and the distributed Bragg reflection laser tuning technology DBR used in the existing optical frequency domain reflectometer devices and methods all use different oscillation start / stop modes. The laser longitudinal mode is used to realize the tuning of the pump beam, and the time delay and phase noise introduced thereby restrict the improvement of the tuning speed and tuning accuracy of the pump light source.

In addition, when the interference method is used to demodulate the measurement signal of the optical frequency domain reflectometer device and method, the deviation of the polarization state between the reference beam and the measurement beam will also lead to a decrease in the accuracy of the measurement result

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