Thin film optical waveguide and preparation method therefor

Abstract

A thin film optical waveguide includes a silicon-based substrate, a cladding layer arranged on the silicon-based substrate, and an optical waveguide core layer arranged on the silicon-based substrate. The optical waveguide core layer is arranged in the cladding layer, the refractive index of the optical waveguide core layer is higher than that of the cladding layer, the optical waveguide core layer includes a double-layer optical waveguide dielectric thin film and a thin film material interlayer arranged between the double-layer optical waveguide dielectric thin film, the thin film material interlayer has a two-dimensional lattice sub-wavelength structure, and the effective lattice constant and the duty cycle of the two-dimensional lattice sub-wavelength structure are approximately the same in each propagation direction, so as to make the effective refractive index of the thin film optical waveguide approximately isotropic.

Dependencies are inferred from the claim text.