Y waveguide chip extinction ratio measuring method and system based on birefringence dispersion compensation

The invention belongs to the technical field of optical coherence domain polarization measurement, and particularly relates to a Y waveguide chip extinction ratio measurement method and system based on birefringence dispersion compensation. The invention discloses a Y waveguide chip extinction ratio measurement method based on birefringence dispersion compensation. The method comprises the following steps: obtaining an interference signal of the extinction ratio of a Y waveguide chip influenced by dispersion; compensating for the third order birefringence dispersion variably based on the degree of symmetry of the interference signal area; compensating second-order birefringence dispersion based on the concentration degree change of the interference signal area after third-order birefringence dispersion compensation; and obtaining the extinction ratio of the Y waveguide chip based on the interference signal after the second-order birefringence dispersion compensation. According to the method, the relationship