| 摘要 |
PROBLEM TO BE SOLVED: To obtain wavelength loss characteristics which are nearly completely flat in a passing area by using multimode interface(MMI) waveguides and connecting two array waveguides in point-symmetrical arrangement on one substrate opposite each other. SOLUTION: A 2nd array waveguide 30 has the same structure with a 1st array waveguide 20 on the other side on a substrate 10 and is arranged opposite the waveguide 20 in a point symmetrical state and also connected to the waveguide 20 through an MMI waveguide 7 which is increased in core width so that higher-order modes can be propagated as well as a basic mode. The light from an input channel waveguide 11 is made incident on a lens 14a. A channel waveguide array 13 is made longer sequentially by desired waveguide length, so the light convergence position changes when a lens 14b is used. The 2nd array waveguide 30 is upside-down, so the position of the light returns to the same position as the light is propagated in a channel waveguide array 23, and the loss becomes equal. |
