Lithium niobate electro-optical phase modulator(lithium niobate modulator) based on titanium diffusion process has the characteristics of low insertion loss, high modulation bandwidth, low half wave voltage, high damage optical power, etc. It is mainly used in the fields of optical chirp control in high-speed optical communication systems, phase shift in coherent communication systems, generation of sidebands in ROF systems, and reduction of stimulated Brillouin scattering (SBS) in analog optical fiber communication systems.