| 摘要 |
PROBLEM TO BE SOLVED: To improve the optical waveguide characteristic of a second projected type core waveguide by eliminating a rise of an intermediate clad layer to make the layer flat. SOLUTION: On a substrate 1, a bottom clad layer 2 and a first projected type core waveguide 31 are formed and the intermediate clad layer 4 is piled up. Then, the layer 4 is made flat by grinding technique and is made thinner by reactive ion etching. Moreover, a second projected type core waveguide 51 is formed and a top clad layer 6 is formed. Since the layer 4, which is the base of the waveguide 51, is ground and is made flat, the optical transmission characteristic of the waveguide 51 is improved. |
