Test device and method of Verdet constant of doped optical fiber

Abstract

The invention discloses a test device and method of the Verdet constant of a doped optical fiber. The test device includes an ASE light source, a collimator, a polarizer, a chopper, a lens, an optical fiber tri-axial displacement stage, a solenoid, a direct-current power source, an analyzer, a photoelectric detector, a lock-in amplifier and a computer; and an doped optical fiber to be measured needs no welding and is directly arranged into the center channel of the solenoid so as to be tested. According to the test device of the invention, the chopper and the lock-in amplifier are adopted, so that noises in an optical path can be effectively inhibited, and the accurate measurement of the Verdet constant can be realized; and in a testing process, the angle of the analyzer does not need to be adjusted for many times, and it only needs to switch on and switch off a power source and record the readings of the lock-in amplifier. Compared with a conventional optical fiber Verdet constant test device, the test device of the Verdet constant of the doped optical fiber provided by the invention has the advantages of no welding loss, excellent anti-noise performance, high sensitivity and simple operation, and is suitable for the measurement of the Verdet constants of various kinds of doped silica optical fibers or glass optical fibers.

Description

technical field [0001] The invention relates to a test device and method for doping optical fiber Verdet constant, belonging to the technical field of optical fiber sensing. Background technique [0002] With the continuous development of optical fiber technology, optical fibers are more and more used in various sensors due to their advantages such as small size, light weight, good insulation, anti-electromagnetic interference, and high sensitivity. Among them, optical fiber sensor devices based on the Faraday magneto-optical effect have been developed rapidly, such as magneto-optic modulators, isolators, current transformers, and fiber optic gyroscopes. The Verdet constant is an important parameter to characterize the characteristics of magneto-optical materials. The Verdet constant of the sensing fiber determines the sensitivity of the magneto-optic effect device to a large extent, so the accurate measurement of the Verdet constant of the fiber is very important. [0003]...

AI Technical Summary

Problems solved by technology

There is also a type of glass optical fiber mixed with rare earth ions, phosphate, silicate and other materials, which has a high content of rare earth ions, but its own light transmission is reduced.

Conventional optical fiber Verdet constant measurement devices and methods need to fuse the optical fiber to be tested with a single-mode optical fiber, and the fusion loss between the doped glass optical fiber and the single-mode optical fiber is extremely large, making it impossible to measure

[0004] In addition, the general optical fiber Verdet constant measurement system directly detects the change of the light intensity at the receiving end, without modulating the test beam, so it is inevitable to mix in the optical noise of other wavelengths during the test process, especially when testing wavelengths near the visible light band When the Verdet constant of , the visible light of the surrounding environment will have a great influence on the test results

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