| 摘要 |
PROBLEM TO BE SOLVED: To avoid generation of a large waveguide loss at a portion of a spot size converter by producing a much smoother inclined surface of a waveguide than that of the waveguide manufactured by a conventional technique. SOLUTION: The manufacturing method of an optical waveguide includes three steps. In the first step, a sacrifice layer is produced on the surface of a lower clad layer and a large groove is formed on the sacrifice layer which has a V shape with a small taper angle seen from the flat surface, has side walls that are vertical with respect to the surface and has a large aspect ratio. In a second step, a directional deposition method is used, i.e., a core layer is deposited in the groove by a deposition method (an ECR-CVD method) to easily obtain isotropic deposition and a core layer is formed on the bottom surface of the groove in a self-forming manner and the core layer in which thickness along the vertical direction is increased in the surface as the width is widened from the V-shaped tip and a three dimensional taper shape is provided. In a third step, the core layer is formed into the core of the spot size converter by removing the sacrifice layer. Thus, a connection loss to an optical fiber is greatly reduced by producing the three dimensional taper surface which has an acute angle and is very smooth. COPYRIGHT: (C)2006,JPO&NCIPI |
