OPTICAL SWITCH AND MANUFACTURE THEREOF

PURPOSE:To attain high-speed switching at a high extinction ratio by forming the semiconductor substrate of a III-VI compd. semiconductor and forming the optical waveguides of a II-VI compd. semiconductor. CONSTITUTION:The semiconductor substrate of an optical directional coupler which is constituted by providing the two optical waveguides which are nearly equal in propagation constant in parallel and proximity to each other on the crystal semiconductor substrate, constituted of the III-VI compd. semiconductor and the optical waveguides are constituted of the II-VI compd. semiconductor. For example, the optical waveguides 102, 103 constituted of ZnSSe are disposed on the substrate 101 constituted of the single crystal of (n) type GaAs. Since the optical waveguides are constituted of the thin film of the II-VI compd. semiconductor of the single crystal in such a manner, the propagation loss of light is lessened and the noise level is lowered below the level of signal light. The switching characteristics of the high extinction ratio are thus obtd.