Closed-loop optic fiber gyroscope light path structure with low polarization error

Abstract

The invention relates to a closed loop optical fiber gyro light path structure with low polarization error, which comprises a light source, a optical fiber coupler, a gamma waveguide integrated optical device, a polarization maintaining optical fiber loop and a detector; the light from the light source passes through the optical fiber coupler, the gamma waveguide integrated optical device and reaches the polarization maintaining optical fiber loop, then goes reverse direction to the gamma waveguide integrated optical device to interfere, passes through the optical fiber coupler and finally reach the detector. For reducing polarization error, polarizers are connected both between the light source and the optical coupler and between the detector and the optical coupler. The light path structure of the invention is characterized in low polarization error, can reduce the amplitude type polarization error to 1 / 5 of the original, and intensity type polarization to 1 / 31 of the original, and improves the light path polarization performance considerably.

Description

technical field The invention relates to an optical path structure, in particular to an optical path structure of a closed-loop fiber optic gyroscope. Background technique Fiber optic gyroscope is a new type of inertial device. It has no moving parts in its structure, and has the advantages of small size, low power consumption, fast start-up, large dynamic range, wide accuracy coverage, long life, high reliability, and low batch cost. There are two schemes of open-loop and closed-loop fiber optic gyroscopes. The closed-loop fiber optic gyroscope is more widely used because of its small nonlinear scale factor and high precision. The typical optical path of a closed-loop fiber optic gyroscope is shown in Figure 1. In the figure, 1 is the light source, 2 is the fiber coupler, 3 is the Y-waveguide integrated optical device, 4 is the polarization-maintaining fiber coil, and 5 is the detector. The above five optoelectronic devices are all It is a device with an optical fiber pigt...

AI Technical Summary

Problems solved by technology

For this reason, "Fiber optic gyroscope" published in 1993 mentioned that adding a polarizer in front of the detector can further suppress the intensity-type polarization error, but the article did not detail how to use the polarizer and the requirements for the polarizer

In addition, there is no other public literature report mentioning how to further suppress the polarization error

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