Detection method and device for high-dynamic-range optical time domain reflection

Abstract

The invention relates to the technical field of optical time domain reflectometer, and provides a detection method and device for high-dynamic-range optical time domain reflection. The device comprises a Raman laser and an OTDR detection laser, which are respectively connected to a WDM, wherein a light outlet of the WDM is connected to a light inlet of a circulator; a light receiving and light signal processing module is connected to a light outlet of the circulator; the light receiving and light signal processing module is further connected to a control module; the control module is used forcontrolling a driving pin of the Raman laser, and controlling the Raman laser to emit at least two light pulses with a time interval in a detection time period according to the relevant information ofreflection light. According to a multi-pulse solution, the light pulses can be amplified and detected through forward Raman light pulses, the Raman light pulses can be continuously sent through the Raman laser after the OTDR detection laser is closed in order to directly amplify and detect back Rayleigh scattering light signals or Fresnel reflection light signals generated by the light pulses.

Description

【Technical field】 [0001] The invention relates to the technical field of optical time domain reflectometers, in particular to a detection method and device for high dynamic range optical time domain reflectance. 【Background technique】 [0002] At present, the communication networks of various countries in the world are mainly based on optical fiber transmission, and optical time domain reflectometer (OTDR) is usually used to test the characteristics of optical fiber when constructing and maintaining optical cable lines. OTDR is also an important device in the online monitoring system of optical communication network, and the dynamic range is one of the important technical indicators of OTDR. The larger the dynamic range of the OTDR, the longer the distance of the optical communication line that can be monitored. [0003] The working principle of OTDR is to analyze the length, attenuation, event and other characteristics of the optical fiber by detecting the energy distribut...

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Problems solved by technology

[0005] U.S. Patent US9494484 proposes a scheme for OTDR measurement in an optical path containing a Raman amplifier, but this scheme only sends a single Raman amplified optical pulse when the OTDR detection laser sends an optical pulse. The principle is mainly through Forward Raman pumping amplifies the detection light pulse, which has a very limited effect on improving the dynamic range, and this solution has the problem that the front-end curve is gentler than the back-end curve, and the absolute value of the slope is smaller, that is, the front-end caused by the Raman amplifier is not given. Solution to Measurement Curve Distortion

This problem will lead to the inability to obtain accurate information of the front-end optical fiber through the measurement results, which will have a serious impact on the overall performance of the product

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