Polarization performance measurement method of multifunctional lithium niobate integrated device

Abstract

The present invention provides a polarization performance measurement method of a multifunctional lithium niobate integrated device. The extinction ratio of a waveguide chip, the coupling crosstalk of optical fibers and the distributed extinction ratios of a waveguide input end optical fiber and a waveguide output optical fiber are measured; a polarizer and an analyzer which have different polarization angles are adopted to measure a waveguide many times, so that the internal crosstalk data of the waveguide input and output end optical fiber are obtained; the energy distribution curve of the crosstalk data is calculated, so that the distributed extinction ratios of the optical fibers are obtained; an interference pattern carrying the extinction ratio of the chip and coupling crosstalk information is obtained through measurement; the extinction ratio and the crosstalk are measured through using interference peaks in the interference pattern which are in bilateral symmetry; whether the difference values of measurement results at a left end and a right end satisfy requirements is judged; and if the difference values are large, re-measurement is required until the results meet the requirements. According to the method, detected polarization crosstalk data are measured on the basis of the characteristics of high precision and wide dynamic range of white light interferometry, and therefore, the measurement results are accurate and reliable.

Description

technical field [0001] The invention relates to a method for measuring optical devices, in particular to a method for measuring the polarization performance of a lithium niobate integrated device (Y waveguide). Background technique [0002] Y waveguide is an important part of fiber optic sensing applications (such as fiber optic gyroscope), which determines the measurement accuracy, stability, size and cost of fiber optic sensing systems. Among them, the extinction ratio is an important indicator of the Y waveguide. At present, the testing methods of extinction ratio mainly include rotating analyzer method, optical time domain reflectometry, polarized light interferometry and so on. The rotation method mainly measures the extinction ratio by measuring the ratio of the maximum light energy to the minimum light energy passing through the polarizing device. This method requires frequent adjustment of the light path, and is limited by the measurement method, and the measurement...

AI Technical Summary

Problems solved by technology

This method can realize fast demodulation of the extinction ratio of the polarization maintaining fiber, but when measuring the extinction ratio of the polarization maintaining fiber with a length of more than one kilometer or a large coupling point for birefringence dispersion comparison, due to the influence of dispersion and noise, the measurement There is a certain deviation between the results and the actual results

[0006] In 2016, the applicant of the present invention (CN201610157528.9) proposed a high extinction ratio measurement method for optical fiber polarization devices. When measuring the Y waveguide, the crosstalk mark and the measurement peak are measured synchronously to prevent the introduction of changes in the measurement environment and device connections. Although this method measures the extinction ratio of the Y-waveguide chip and coupling crosstalk, it does not measure the distributed extinction ratio of the input and output fibers, and the measurement results are affected by dispersion, so the results are not accurate

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