Method for manufacturing birefringent integrated optics devices

Abstract

Method for adjusting the value of birefringence in predetermined sections of waveguides in integrated optics devices fabricated in optically anisotropic substrates such as monocrystalline LiNbO.sub.3 or LiTaO.sub.3. The inventive method comprises in combination methods for changing both refractive indices in a first volume of the substrate, such as, for instance, ion implantation or metal in-diffusion, thereby creating an optical waveguide for both TE and TM modes of radiation, and methods for further changing one of the indices in a second volume of the substrate, without proportionally changing the other index in the second volume, such as, for instance, Li out-diffusion or ion exchange. In a typical application, the first volume comprises waveguiding regions, including the section in which the birefringence is to be adjusted, and the second volume also includes that waveguide section. The inventive methods are advantageously employed in the manufacture of integrated optics devices whose operating characteristics depend on the value of birefringence of a section of waveguide, for instance, a mode converter/wavelength filter, or a polarization separator.

Dependencies are inferred from the claim text.