Optical fiber vibration sensing system based on polarization state based on time division multiplexing

Abstract

The invention relates to an optical fiber sensing system, and particularly relates to a time division multiplexing-based polarization state optical fiber vibration sensing system. The system comprisesa first pulse generator. The output end of the first pulse generator is connected with a first light source, a phase inverter and a first data acquisition module. The phase inverter is connected witha second pulse generator. The second pulse generator is connected with a second light source. The first light source and the second light source are connected with a first port of an optical circulator through an optical coupler. The optical circulator is connected with a sensing optical fiber. The optical circulator transmits the scattered light to an optical wavelength division multiplexer through a third port. The optical wavelength division multiplexer is connected with a photoelectric detector through a polarization analyzer. The photoelectric detector is connected with the first data acquisition module. According to the invention, the higher vibration sensing sensitivity is achieved, and meanwhile the higher system stability is achieved.

Description

technical field [0001] The invention relates to an optical fiber sensing system, more specifically, to a polarization state optical fiber vibration sensing system based on time division multiplexing. Background technique [0002] The optical fiber vibration sensing system based on POTDR sensing technology is a new type of sensor that achieves the purpose of distributed optical fiber sensing by detecting the polarization state change in the optical fiber. Because it can detect weak stress changes, it has a wide application prospect. [0003] With the implementation of the urban high-voltage cable laying project from the air to the ground, the current urban power transmission lines basically use the form of underground tunnels to transport electricity. It is more and more important to monitor the safety and health of urban power transmission network, find faults in time, and ensure the normal operation of society. However, the on-site environment of the cable tunnel is very h...

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Problems solved by technology

However, the site environment of the cable tunnel is very harsh, and conventional security alarm equipment cannot be applied at all.

On-site environmental conditions: 1) After long-term use of the underground cable trench, it is easy to accumulate water and silt, and conventional electronic equipment cannot work for a long time in such a harsh environment; 2) There is no 220VAC power supply in the cable tunnel, and conventional electronic equipment cannot supply power. And due to the harsh environment in the underground cable trench, long-distance 220VAC power supply is also likely to cause leakage hazards

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