Double-Y-branch optical waveguide phase modulator

The invention discloses a double-Y-branch optical waveguide phase modulator, which comprises a light source, a phase modulator chip and an optical fiber ring which are connected in sequence, wherein the phase modulator chip is further connected with a photoelectric detector and a signal processing circuit in sequence, the phase modulator chip comprises a substrate, a first Y-branch optical waveguide, a second Y-branch optical waveguide and a base waveguide, the first Y-branch optical waveguide, the second Y-branch optical waveguide and the base waveguide are manufactured on the substrate, the output end of the first Y-branch optical waveguide is connected with one end of the base waveguide, the other end of the base waveguide is connected with the input end of the second Y-branch optical waveguide, and the output end of the first Y-branch optical waveguide deviates from the input end of the second Y-branch optical waveguide in the direction perpendicular to optical signal propagation by a distance d ranging f