Thin-film lithium niobate-based integrated chip and preparation method thereof

The invention discloses a thin-film lithium niobate-based integrated chip and a preparation method thereof. A substrate material is silicon-based thin film lithium niobate; the waveguide is a lithiumniobate ridge waveguide; the structure comprises an input/output port, a Mach-Zehnder electro-optic intensity modulator and a coupled double-ring resonator, a Mach-Zehnder modulator comprises two 1*2multimode interference couplers, two modulation arms and a GSG electrode, two coupling regions of the coupled double-ring resonator adopt coupling coefficient tuning units based on a Mach-Zehnder interference structure, and regulation and control electrodes are arranged in the coupling regions and the cavity; a radio frequency signal is loaded to an optical carrier through the modulator and thenis processed by the resonator, and the output signal is output to a detector or other unit chips through the output end, so that the functions of filtering, time delay and the like are realized. The electro-optical modulator and