Distributed optical fiber loss measurement system based on Raman scattering and measurement method thereof

Abstract

The invention discloses a distributed optical fiber loss measurement system based on Raman scattering and a measurement method thereof. The measurement system is connected with an optical fiber to bedetected, and comprises a pulse laser, a directional coupler, a beam splitter, a photoelectric detector, a high-speed signal collector, a main control computer and a laser driving circuit which are sequentially connected; the laser driving circuit is also connected with the high-speed signal collector and the pulse laser; the optical fiber to be detected is connected with the directional coupler,the main computer controls the laser driving circuit and high-speed signal collector, and performs data processing and result report, the photoelectric detector detects the light reflected from the optical fiber to be detected through Raman scattering. According to the invention, the measurement precision can be greatly improved, and interference items such as temperature and the like can be eliminated; and the temperature distribution of the optical fiber can be monitored in real time while the loss distribution of the optical fiber is detected.

Description

Technical field: [0001] The invention belongs to the technical field of optical fiber communication, in particular to a Raman scattering-based distributed optical fiber loss measurement system and a measurement method thereof. Background technique: [0002] As short-distance optical communication systems such as passive optical network (PON) are used more and more in residential areas, buildings, etc., the loss caused by various factors in optical fibers is also increasing, and it is becoming more and more difficult to avoid. In a short-distance (about a few kilometers to tens of kilometers) optical fiber system with dense and complex networks, it is becoming more and more important to be able to timely and accurately measure the loss distribution on the entire optical fiber during fiber layout and use, and its positioning accuracy The requirements are also getting higher and higher. Especially after the fiber optic laying is completed, the fiber loss at one or some points ...

AI Technical Summary

Problems solved by technology

However, there are many interferences in short-distance complex environments, including temperature, vibration, etc., which may cause changes in the intensity of reflected light, resulting in misjudgment

In addition, the positioning accuracy of OTDR based on the principle of Rayleigh scattering is poor, usually only up to hundreds of meters or even a few kilometers, and the measurement is not accurate within the initial tens of kilometers, so it is not suitable for short-distance complex optical fiber systems in essence. Short-distance high-precision detection required

Although people improve by adding additional optical fibers and improving the accuracy of pulse measurement, OTDR can be used for short-distance optical fiber fault location, but its accuracy is still poor, and it often needs to cooperate with other measures or manually for more accurate fault location; for optical fiber It is even more difficult to use OTDR to detect the situation that there is no major fault such as fracture, but the loss is abnormally increased.

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