| 摘要 |
PROBLEM TO BE SOLVED: To provide a directional optical coupler that can vary the phase characteristics of polarized wave component of propagating light is variable. SOLUTION: The directional optical coupler (1) has two straight optical wave guides (2, 3), having cores (2a, 3a) which are close to each other and extending in the longitudinal direction (1a) for forming an optical coupler part and the central lines (2d) of the cores; and a tapered optical waveguide (4), having a core (4a) connected to the core (2a) of at least one of straight optical wave guides (2). The core width of the tapered optical waveguide (4) is made to narrow as going toward at least one of the straight optical wave guides (2). The shape of the tapered optical waveguide (4) is asymmetric, with respect to the center line (2d) of at least one of the straight optical wave guides (2). COPYRIGHT: (C)2007,JPO&INPIT |
