| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical waveguide coupler, capable of readily making an optical waveguide couple with a resonator by relaxing a phase matching condition. SOLUTION: Light in a multi-mode optical waveguide 1 is coupled directly with a fine spherical resonator 2 via an evanescent light. Since the minute spherical resonator 2 is minute, coupling efficiency between the minute spherical resonator 2 and the multi-mode optical waveguide 1 is low. Thus, the influence from the minute spherical resonator 2 is weak in a non-resonance condition so that light propagation in the multi-mode optical waveguide 1 is not affected. However, the intensity of light stored in the minute spherical resonator 2 is strong in the resonance condition, the minute spherical resonator 2 emits to the multi-mode optical waveguide 1 the same level as that in the multi-mode optical waveguide 1, even with low coupling efficiency. Thus, a strong coupling condition is always realized, thereby the role as a filter is fulfilled by interference between light in the multi-mode optical waveguide 1 and light passing through the minute spherical resonator 2. |
