Optical waveguide device and process for production thereof
AssigneeNEC Corporation
InventorToshiyuki Kambe
Life of this patent
Estimating the term…
Abstract
An optical waveguide device wherein a substrate is fabricated from a lithium niobate (LiNbO3) substrate; at least one optical waveguide is formed in the lithium niobate substrate in such a manner that two Mach-Zehnder type directional couplers are formed, and further a phase shifter is formed in between these directional couplers; and the phase shifter is provided with an electrode of a structure including a first thin film layer being an ITO thin film containing an oxide and a second thin film layer being a chromium thin film an oxide of which is acidic, whereby an electric field produced in response to a voltage applied to the electrode is given to the optical waveguide to function as a variable optical attenuator.
Claims12
An optical waveguide device, comprising:
- a substrate;
- at least one optical waveguide disposed in said substrate;
- a first conductive thin film layer placed in the vicinity of or on the top of said optical waveguide in said substrate and containing an oxide;
- and
- a second conductive thin film layer laminated on said first thin film layer and exhibiting acidic or neutral characteristics in its oxidized condition.
A process for the production of an optical waveguide device, comprising the steps of:
- forming at least one optical waveguide in an LN (lithium niobate) substrate;
- forming an ITO film on said optical waveguide and the surface of said LN substrate;
- forming a photoresist on said ITO film to conduct a patterning operation;
- removing unnecessary portions of said ITO film by means of etching with use of said photoresist as a mask to form the ITO pattern;
- removing the photoresist on said ITO pattern;
- forming a chromium thin film having a thinner film thickness than that of said ITO film on the surface of said ITO pattern and an exposed surface of said substrate;
- applying a photoresist on said chromium thin film;
- removing unnecessary portions of said chromium thin film by means of etching;
- and
- removing the photoresist remained on said chromium thin film after said etching.
Dependencies are inferred from the claim text.