| US 7,593,610 B2 | ||
| Multi-mode optical coherence device and fabrication method thereof | ||
| Hiroshi Wada, Tokyo (Japan) | ||
| Assigned to Oki Semiconductor Co., Ltd., Tokyo (Japan) | ||
| Filed on Dec. 04, 2006, as Appl. No. 11/607,992. | ||
| Claims priority of application No. 2005-351802 (JP), filed on Dec. 06, 2005. | ||
| Prior Publication US 2007/0127868 A1, Jun. 07, 2007 | ||
| Int. Cl. G02B 6/26 (2006.01); B02B 6/42 (2006.01); B02B 6/10 (2006.01) | ||
| U.S. Cl. 385—39 [385/28; 385/29; 385/129] | 3 Claims |
| 1. A manufacturing method for an optical multimode interference device comprising a multimode waveguide having one or more
narrow width single-mode waveguides provided at both ends thereof, wherein light introduced into the one or more single-mode
waveguides at an input side of the device is interfered within the multimode waveguide and emitted from the one or more single-mode
waveguides at an output side of the device, the manufacturing method comprising:
(a) on a crystal substrate which is a lower cladding layer, sequentially forming an optical waveguide layer, an upper cladding
layer, and a mask layer for etching;
(b) patterning the mask layer to form a mask pattern which corresponds to the multimode waveguide and the one or more single-mode
waveguides;
(c) selectively wet etching the upper cladding layer, using the mask pattern as a mask, to form the upper cladding layer such
that, at both ends of said multimode waveguide, a wall face that is not provided with the one or more single-mode waveguides
has a predetermined inclination angle along the crystal plane of the upper cladding layer; and
(d) dry etching said upper cladding layer, said optical waveguide layer, and said crystal substrate using the mask pattern
as a mask, to remove these layers to a predetermined thickness in a perpendicular direction, with the wall faces of the optical
waveguide layer maintaining said predetermined inclination angle.
|