Production method for all-fibre quarter-wave plate

Abstract

The invention relates to the field of all-fibre current transformer, particularly to a production method for an all-fibre quarter-wave plate. The invention provides a production method for an all-fibre quarter-wave plate aiming at the problems existed in the prior art, capable of efficiently solving the two difficult problems of a control to an axis angle and a precise interception to the 1 / 4 beat of length by a polarization maintaining optical fibre. The invention detailedly explains a production method for an all-fibre quarter-wave plate via a series of steps, and solves the problems existed in the prior art. The method is mainly applied to the production field of quarter-wave plate.

Description

technical field [0001] The invention relates to the field of all-fiber-optic current transformers, in particular to a method for manufacturing a quarter-wave plate in an all-fiber-optic current transformer. Background technique [0002] For the development of all-fiber-optic current transformers, the annular or reflective Sagnac interferometer scheme is currently used. This scheme draws on the relatively mature fiber-optic gyroscope technology at present. The optical path structure, detection method, and key technology of these two technologies Almost exactly the same, the only difference is that the all-fiber current transformer has one more key optical device than the Sagnac-type fiber optic gyroscope—a quarter-wave plate, whose main function is to convert the linearly polarized light on the transmission line into a sensor for sensing. Circularly polarized light is the transition point between the transmitted optical signal and the sensory optical signal, thus using the Fa...

AI Technical Summary

Problems solved by technology

[0003] The quarter-wave plate plays a key role in the polarization state of the optical signal in the all-fiber current transformer, but because it cannot learn from the current relatively mature fiber optic gyroscope technology, this device has become the most difficult part in the development of the all-fiber current transformer. one of the places

[0004] The function of a quarter-wave plate can be realized through a polarization controller, a crystal wave plate, and an all-fiber wave plate. The structural design of the polarization controller is very complicated and is not suitable for application in engineering implementation; the temperature characteristic of the crystal wave plate itself is better. , but there is the problem of spatial light coupling to the optical fiber, and the stability is poor; the all-fiber quarter-wave plate made of optical fiber has a simple and compact structure, has a larger bandwidth, and can better connect with the front and rear fibers , and good stability

[0005] The production principle and process of the all-fiber quarter-wave plate are very simple. It is made by splicing two sections of polarization-maintaining optical fiber at 45° to the axis, and then intercepting the quarter-beat length of the optical fiber at the output end. However, in the production process Inevitably, there are two major difficulties: the first is the control of the axis angle of the polarization maintaining fiber, that is, the axis angle cannot be completely controlled to 45° when two sections of polarization maintaining fiber are spliced ​​at 45°, and there will be a certain deviation (generally within ± 0.7°); Secondly, it is more difficult because the beat length of the polarization maintaining fiber is generally a few millimeters (the beat length is a basic parameter of the polarization maintaining fiber, and its index is generally in the range of 2mm to 10mm, the highest in the world The indicator does not exceed 30mm, and can only reach about 20mm), so it is difficult to accurately intercept a quarter of the length of the shot at the millimeter level

The two major difficulties in the production of the all-fiber quarter-wave plate lead to certain errors in the fabricated wave plate, which leads to errors in the all-fiber current transformer, making its measurement accuracy fail to meet the measurement requirements of the power system

[0006] The two major difficulties in the production process of the all-fiber quarter-wave plate are common problems in the field of optical fiber sensing in the world at present, especially the difficulty of accurately intercepting the quarter-wave length, which makes the device become an all-fiber current transformer. The biggest bottleneck in the development process

Images