Polarization characteristic parameters measurement of Y-waveguide multifunction integrated optic circuit based on noise reduction processing

Abstract

The polarization characteristics of the lithium niobate multifunction integrated optic circuit (MIOC), including its polarization extinction ratio (PER) and pigtail crosstalk, have a significant impact on the accuracy of fiber optic gyroscopes. A distributed polarization coupling (DPC) MIOC polarization parameter measurement method based on noise reduction processing is proposed. The proposed method aims to classify signal components decomposed by complete ensemble empirical decomposition with adaptive noise (CEEMDAN) by setting the threshold of the autocorrelation coefficient to filter out noise components. By setting the dynamic threshold and step size, DPC points are adaptively extracted from the denoised signal and superimposed to calculate the PER and pigtail crosstalk. Compared with empirical mode decomposition and ensemble empirical mode decomposition methods, the PER value obtained by the CEEMDAN method has the best consistency with the measured value of a commercial extinction ratio meter, the mean difference is 0.014 dB, and the pigtail crosstalk is −43.77 dB.