Distributed optical fiber sagnac positioning sensor inhibiting dead zone of sensor

Abstract

The invention relates to a distributed optical fiber sagnac positioning sensor inhibiting the dead zone of a sensor, which is characterized by comprising a first optical fiber coupler and a second optical fiber coupler; the light-inlet port of the first optical fiber coupler is a second port, and the light-outlet port of the first optical fiber coupler is a first port, a third port, a fourth port, a fifth port and a sixth port; the third and the fourth ports of the first optical fiber coupler are mutually connected by a delay optical fiber, a photoelectric detection unit is arranged in front of the first port of the first optical fiber coupler, and the output signal of the photoelectric detection unit is switched in an A / D conversion digital collection card which is electrically connected with a computer; the sensor also comprises a sensing optical fiber and the second optical fiber coupler; and a reference light source is arranged in front of the second port of the first optical fiber coupler, and an optoisolator is arranged between the reference light source and the second port. The invention reduces insertion consumption, and the delay of optical fiber length by reasonable selection can not only inhibit sensing dead zone in the sensing optical fiber, but also eliminate pseudo-zero frequency points appearing in signal demodulation, and improve the signal-to-noise ratio.

Description

technical field [0001] The invention relates to the field of optical sensors, in particular to a distributed optical fiber sagnac positioning sensor that suppresses the dead zone of the sensor. Background technique [0002] In the fiber optic Sagnac interferometer, the light coming out of the light source is divided into two beams by the coupler, which propagate along the clockwise and counterclockwise directions of the fiber ring respectively. When a point in the fiber is disturbed by external changes, the light beam passing through this point will phase change. The two counter-propagating lights pass through this point at different times, so that the additional phase changes generated are not equal. When the two counter-propagating lights return to the coupler, interference occurs, and the relevant position information can be obtained by demodulating the signal. Since the two paths of interfering light propagate in the same optical path, but the direction of propagation i...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a distributed optical fiber sagnac positioning sensor that suppresses the dead zone of the sensor, to solve the problem that the traditional technology has a sensing dead zone, and the optical cycle of the traditional technology easily leads to the weakening of the interference signal intensity

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