On-Chip Microstructure Stmulation Based On The Lithium Niobate Thin Film Waveguide

In this thesis,we simulate the functionalities of optical devices on Lithium niobate thin film,including spontaneous parametric down-conversion(SPDC)pro-cess in the periodic polarized waveguide,electro-optic phase modulator,and di-rectional coupler.The main results are as follow:1.Spontaneous down-conversion process in the periodic polarized waveguide In the simulation,we first calculate the size of the double-fundamental mode waveguide of light with a wavelength of 810nm.Then,we simulate the SPDC process of 405nm→ 810nm under different conditions.Finally,we conclude that the polarization period is 3.43μm under current experimental technology.2.Electro-optic phase modulator is one of the most basic components in integrated optics.It has the function of modulating the phase of the transmitted light in the waveguide.For the light with a wavelength of 810nm,we calculate the half-wave voltage length product of the double-mode waveguide.For the E00x mode,the half-wave voltage length product can be as low as 0.8V·cm.3.Directional coupler is another basic element in integrated optics.We sim-ulated the coupling efficiency with the changes of waveguide width,etching thick-ness,sidewall angle,and waveguide gap.We observe that the coupling length increases with the increase of waveguide width,etching thickness,sidewall angle,and waveguide gap.With these calculations,we design two kinds of multifunc-tional directional couplers.