Measuring device and method of modal birefringence for high-birefringence polarization-maintaining fibers

Abstract

The invention discloses a measuring device and method of modal birefringence for high-birefringence polarization-maintaining fibers. The measuring device comprises a wide-spectrum light source, a polarizer, an electrooptical modulator, a high-birefringence polarization-maintaining fiber under measurement, a polarization analyzer, a photoelectric detector, a frequency mixer, a data acquisition circuit and a computer, as well as a frequency sweep signal source, a microwave power divider, and a microwave phase shifter. The electrooptical modulator modulates a first microwave signal to light to form a light-carried microwave signal; the light-carried microwave signal passes through the high-birefringence polarization-maintaining fiber under measurement to form two light-carried microwave signals having different optical path differences; the two light-carried microwave signals having different optical path differences pass through a photoelectric detector and are input to the radio frequency input end of the frequency mixer; the frequency mixer performs frequency mixing on the two light-carried microwave signals having different optical path differences and the second microwave signal,a medium-frequency signal passes through a low-pass filter, and a direct-current signal is input to the data acquisition circuit; the data acquisition circuit inputs frequencies at the different amplitude parts of the direct-current signal to the computer for computing. The measuring device and method herein provide precise measurement for the modal birefringence of high-birefringence polarization-maintaining fibers.

Description

technical field [0001] The invention relates to the technical field of optical fiber measurement, in particular to a device and method for measuring mode birefringence of high birefringence polarization-maintaining optical fibers. Background technique [0002] High-birefringence polarization-maintaining optical fibers are widely used in fields such as fiber optic gyroscopes, fiber optic current transformers, and polarization-maintaining optical devices. In these applications, the polarization-maintaining performance of the polarization-maintaining fiber is the key to determine its application. Generally, the mode birefringence or beat length is used to measure the polarization-maintaining performance of the polarization-maintaining fiber. Among them, the mode birefringence of the high-birefringence polarization-maintaining fiber is equal to The magnitude of the refractive index difference between the two polarization eigen axes of the polarization maintaining fiber. [0003...

AI Technical Summary

Problems solved by technology

The above methods are all based on optical principles to measure the mode birefringence of high birefringence polarization-maintaining fibers. Different optical principle measurement methods will have deviations in accuracy and will be affected by measurement tools and the environment.

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