Dual-polarization-state analyzer for vibration sensing

Abstract

The invention discloses a dual-polarization-state analyzer for vibration sensing. An incident light is cast to a light splitter via a first optical fiber collimator, and a first beam and a second beam are generated. The first beam is vertically cast to a first polarizer, and the light emitted from the first polarizer goes through a second optical fiber collimator. The second beam is vertically cast to a second polarizer, and the light emitted from the second polarizer goes through a third optical fiber collimator. The range of the angle between light transmission axis of the first polarizer and the light transmission axis of the second polarizer is 5 degrees to 85 degrees. The invention provides the dual-polarization-state analyzer, the cost of needed optical devices is low, the structure is simple, under the condition of increasing little cost, the influences of instable environment factors such as a temperature, a deployment mode and a non-polarization-maintaining fiber quality difference can be overcome, and the vibration sensing sensitivity is high. The invention provides a cost-limited fiber polarization detection vibration sensing system solution, and vibration characteristics can be detected through polarization state changes in an unstable environment.

Description

technical field

[0001] The invention belongs to the technical field of optical fiber sensing, and more specifically relates to a dual polarization analyzer for vibration sensing. Background technique

[0002] A light wave is a transverse wave with polarization properties. The presence of vibrations can be determined by using the effect of vibrations on the polarization state of a beam of light within an optical fiber. In a cost-constrained fiber optic vibration sensing system, only a single analyzer can be used to determine whether vibration has occurred on the sensing fiber line. However, the polarization state of the beam emitted by the light source changes with temperature. This problem may cause fluctuations in the sensitivity of the optical fiber polarization state detection vibration sensing system, and then false positives or false positives of the sensing system may occur. Adding a polarization controller to stabilize the light source may bring a relatively large ...

Images