Interferometry-based optical fiber Verdet constant measuring system

Abstract

The invention discloses an interferometry-based optical fiber Verdet constant measuring system. The system comprises an ASE (amplified spontaneous emission) light source, a single-mode optical fiber coupler, a Y-waveguide integrated optical modulator, 1 / 4 wave plates, Faraday rotator mirrors, a solenoid, a sine alternating-current driving circuit, matching fluid, a probe, an information processing module, a computer and measured optical fibers. The ASE light source, the single-mode optical fiber coupler, the Y-waveguide integrated optical modulator, the measured optical fibers and the Faraday rotator mirrors are connected through optical fibers in sequence. Each 1 / 4 wave plate is arranged between the Y-waveguide integrated optical modulator and the corresponding measured optical fiber. A signal processing portion comprises a feedback servo circuit, an FPGA (field programmable gate array) module and a phase modulation driving circuit. The system is of an all-optical-fiber structure and simple and convenient to set up; by the aid of the Faraday rotator mirrors, influences of linear birefringence of the optical fibers on measurement can be eliminated, and measurement accuracy is improved; and Verdet constants of various optical fibers can be measured by the system.

Description

technical field [0001] The invention relates to the field of optical applications, in particular to a measurement system for measuring the Verdet constant (Verdet constant) of an optical fiber by using an interferometry. Background technique [0002] With the development of optical fiber technology, due to the advantages of strong anti-interference ability, good insulation, good high temperature resistance, and high sensitivity, optical fiber sensors using optical fibers as sensing devices have emerged as the times require. Among them, fiber optic gyroscope and fiber optic current transformer are two typical fiber optic sensors. [0003] As an important angular velocity sensor, fiber optic gyroscope has important applications in various civil and military positioning and navigation systems. In practical applications, the fiber optic gyroscope is disturbed by environmental factors such as magnetic field, temperature, vibration, etc., which will cause signal drift and greatly...

AI Technical Summary

Problems solved by technology

However, in the dual optical path measurement, the signal processing is carried out through the "difference and sum" measurement scheme, which requires that the polarization direction of the linearly polarized light is at an angle of 45° with the direction of the splitting axis of the polarizing beam splitter (PBS), so the position of the PBS is placed It has a great influence on the measurement of the system, resulting in inaccurate measurement of the system

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