OPTICAL COUPLER CAPABLE OF CONNECTING THIN WIRE WAVEGUIDE AND RIDGE WAVEGUIDE WITH LOW LOSS

摘要

An optical coupler comprises a ridge core (32) having one end connected to the core (31) of a ridge waveguide (30). The ridge core (32) comprises a thin-film part (32a) and a ridge-shaped projecting part (32b) formed on the thin-film part (32a). The height of the thin-film part (32a) is reduced from one end toward the other end. The optical coupler further comprises a thin wire core (22) having one end connected to the other end of the ridge core (32) and the other end connected to the core (21) of a thin wire waveguide (20). The height of the thin wire core (22) is reduced from one end toward the other end.