A High Dynamic Range Optical Time Domain Reflectometry Detection Method and Device

Abstract

The invention relates to the technical field of optical time domain reflectometer, and provides a high dynamic range optical time domain reflectance detection method and device. The device includes a Raman laser and an OTDR detection laser connected to the WDM respectively, and the optical outlet of the WDM is connected to the optical inlet of the circulator; the optical receiving and optical signal processing module is connected to the optical outlet of the circulator; the optical receiving and optical signal processing module is also connected to the control module; The module is used to control the drive pin of the Raman laser, and control the Raman laser to emit at least two light pulses with a time interval within a detection time period according to the information related to the reflected light. The multi-pulse solution of the present invention can not only amplify the detection light pulse through the forward Raman light pulse, but also directly amplify the detection light pulse generated by sending multiple Raman light pulses through the Raman laser after the OTDR detection laser is turned off. Rayleigh backscattered light signals and / or Fresnel reflected light signals.

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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