Research On Optimization Design And Light Propagation Characteristics Of Vanadate Crystal Waveguide Structure

The optical waveguide structure which is formed by the high refractive index medium, is surrounded by low refractive index medium. In the waveguide structure,waveguide is a kind of narrow channel of light transmission components, which makes the light limit in a micron region particular medium or the surface, and it can make the light waves propagated along a certain direction. By studying on the optical waveguide preparation of micro optical element,and making them connected with specific functions of the optical system which is called integrated optics.In the paper, we study the basic structure of the waveguide theory and the method of preparation. Used the classical electromagnetic theory and linear optical theory as the foundation, we deduced pump threshold of strip optical waveguide under the different level and slop efficiency of the waveguide. This paper introduced the basic solving process of the beam propagation method, and the Maxwell equation is used to derive TE mode and TM mode distribution.The main index of evaluating waveguide properties is optical waveguide transmission loss, in order to design a low loss and high efficiency of waveguide, based on the Rsoft simulation software and the finite difference beam propagation method, we have optimized the Yb:YVO4 and Yb:LuVO4 and Yb:GdVO4 crystal single waveguide,double waveguide and cladding waveguide's optimal parameters such as the refractive index difference between waveguide and material, the size of the waveguide. The optical waveguide which is adopted by this paper is done by femtosecond laser micro processing technology, we mainly studied the light propagation properties of the Yb:vandate crystal waveguide under different structure parameters.and simulated the laser intensity distribution of Yb:vandate crystal waveguide under different structuure parameters. By choosing specific parameter range, the light in the waveguide is propagated only as base model form, and the near filed intensity distribution is stable, scattering loss is low,model conversion loss disappeared. The transmission loss is reduced effectively by controlling the waveguide parameters, and the stability of the near filed intensity distribution is improved. The simulation results provide a rigid theoretical base for the microfabrication a varity of crystal waveguide and the design of femtosecond laser.