Dynamic frequency offset correction method and coherence optical time-domain reflectometer system

Abstract

The invention discloses a dynamic frequency offset correction method and a coherence optical time-domain reflectometer system. The method comprises the steps of light splitting of laser output by a laser to generate probe light and control light; inputting the control light into an MZI for interference and performing photoelectric conversion on the interfered control light to obtain a first electric signal; controlling optical path difference of optical signal transmitted at two arms of the MZI according to the first electric signal so that the optical path difference is one quarter of the wavelength of the laser; according to the first electric signal, calculating a deviation degree of an actual central frequency of the laser relative to a standard value of the central frequency of the laser; and compensating correspondingly based on the deviation degree. According to the method of the present invention, the laser output from the laser is divided into the probe light and the control light and the deviation degree of the actual central frequency of the laser relative to the standard value of the central frequency of the laser is obtained according to the control light. In addition, the laser output from the laser is correspondingly corrected and controlled according to the deviation degree so as to improve performance of optical coherent detection.

Description

technical field [0001] The invention relates to the technical field of optical fiber communication, in particular to a dynamic frequency offset correction method and a coherent optical time domain reflectometer system. Background technique [0002] With the development of optical fiber communication technology, the optical fiberization of the network has always been one of the main trends in network development. The submarine optical cable is a very important part of the network optical fiber, and the real-time monitoring of the long-distance submarine optical cable has also become an important content of network maintenance. [0003] When testing submarine optical cables, a coherence optical time-domain reflectometer (hereinafter referred to as COTDR) is used for testing. In the COTDR system, due to the need to detect ultra-long-distance laser reflection signals, the laser is in Frequency drift during the measurement will affect the receiver receiving frequency. In order ...

AI Technical Summary

Problems solved by technology

However, the existing technology has the following disadvantages: due to the high requirements on the line width of the light source in COTDR, the adjustment of the frequency of the light source will affect the line width of the light source, therefore, it will affect the detection effect

Images