| 摘要 |
PROBLEM TO BE SOLVED: To reduce the asymmetry of a mode profile in an optical waveguide in which the mode profile is asymmetric in the core cross section. SOLUTION: On the upper face of the lower clad layer 23, a core groove 25 having a trapezoidal cross section with a wider upper side is formed. In the core groove 25, a core 26 is formed the upper side of which is sealed with an upper clad layer 24. The bottom face of the core groove 25 is formed with a low refractive index layer 27 having a smaller refractive index than the lower clad layer 23, which consequently increases an essential difference in the refractive index between the core 26 and the lower clad layer 23. COPYRIGHT: (C)2005,JPO&NCIPI |
