Fabrication method for uniform planer optical waveguide

A method for manufacturing a planar optical waveguide uniform, the method comprising the steps of: (a) depositing on a substrate a lower cladding layer, depositing and polishing the surface; on the resulting structure (b) in step (a) depositing a core layer and polished the deposition surface; (c) to step (b) in which the polished surface of the core layer is patterned to obtain an optical waveguide; and (d) depositing a cladding layer on the optical waveguide after step (c) is formed by patterning. Since further comprising the step of polishing the surface, thus improving the uniformity of the thickness of the optical waveguide. As a result, the effective refractive index in the optical waveguide becomes uniform, and can be manufactured more precise optics. Phase matches with the expected value of each channel, thereby reducing crosstalk.