| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a waveguide type optical coupler in which the coupling efficiency by multimode optical interference waveguides is made to be a stable value that is beforehand set even though the incident positions of optical signals into optical input waveguides are deviated to a certain extent. SOLUTION: A multimode optical interference waveguide 2 is connected to the output sides of optical input waveguides 1a and 1b in which two waveguides are arranged in parallel, respectively. Optical output waveguides 3a and 3b in which two waveguides are arranged in parallel are connected to the emitting side of the waveguide 2. The width of the waveguide 2 is made wider than the widths of the waveguides 1a, 1b, 3a and 3b. Narrow width linear waveguides 5 are arranged between the waveguides la and 1b and the waveguide 2 and between the waveguides 3a and 3b and the waveguide 2. The widths of the waveguides 5 are made narrower than the widths of the corresponding waveguides 1a, 1b, 3a and 3b.</p> |
