| 摘要 |
PROBLEM TO BE SOLVED: To prevent cracking in a core layer, to improve the transmission efficiency in an optical device and to improve the mechanical strength of the optical device. SOLUTION: In the optical device 10A equipped with a first clad layer 14 on a substrate 12, a core layer 16 functioning as an optical waveguide formed on the surface of the first clad layer 14, and a second clad layer 20 formed on the surfaces of the first clad layer 14 and the core layer 16, a crack groove 28 is formed on the surface of the first clad layer 14 at the root of one or more projections 22 so as to prevent cracking on the boundary 30 between the core layer 16 and the first clad layer 14. |
