Abstract: There is provided a semiconductor device that includes a III-V Group compound semiconductor having a zinc-blende-type crystal structure, an insulating material being in contact with the (111) plane of the III-V Group compound semiconductor, a plane of the III-V Group compound semiconductor equivalent to the (111) plane, or a plane that has an off angle with respect to the (111) plane or the plane equivalent to the (111) plane, and an MIS-type electrode being in contact with the insulating material and including a metal conductive material.

Abstract: It is an objective of the present invention to form a favorable interface between an oxide layer and a group 3-5 compound semiconductor using a practical and simple method. Provided is a semiconductor wafer comprising a first semiconductor layer that is a group 3-5 compound not containing arsenic and that lattice matches or pseudo-lattice matches with InP; and a second semiconductor layer that is formed to contact the first semiconductor layer, is a group 3-5 compound semiconductor layer that lattice matches or pseudo-lattice matches with InP, and can be selectively oxidized relative to the first semiconductor layer.

Abstract: The present invention provides a set-reset flip-flop operating in an all-optical manner. In this invention, a set pulse is inputted from the setting port. In doing so, only oscillation in set mode is generated at the multi-mode interference portion in a waveguide. As a result, a non-inverting output Q is obtained from the non-inverting output port. This state is then continued even if the set pulse input goes off. Next, a reset pulse is inputted to the resetting port. In doing so, at the multi-mode interference portion, oscillation of light in the set mode is halted, and oscillation in the reset mode occurs. As a result, it is possible to obtain an inverting output Q-bar from the inverting output port. This state is then continued even if the reset pulse goes off.

Abstract: The present invention provides a set-reset flip-flop operating in an all-optical manner. In this invention, a set pulse is inputted from the setting port. In doing so, only oscillation in set mode is generated at the multi-mode interference portion in a waveguide. As a result, a non-inverting output Q is obtained from the non-inverting output port. This state is then continued even if the set pulse input goes off. Next, a reset pulse is inputted to the resetting port. In doing so, at the multi-mode interference portion, oscillation of light in the set mode is halted, and oscillation in the reset mode occurs. As a result, it is possible to obtain an inverting output Q-bar from the inverting output port. This state is then continued even if the reset pulse goes off.

Abstract: An optical waveguide isolator for use in an optical communication system is disclosed. The optical waveguide isolator comprises a semiconductive light amplifier structure including a semiconductor substrate of first conductivity type having a surface of a layer to be formed thereon, a first cladding layer of first conductivity type formed on the substrate, an active layer formed on the first cladding layer, a second cladding layer of the second conductivity type opposite to first conductivity type, formed on active layer, a first electrode formed on the surface of the semiconductor substrate opposite to the surface to be formed as a layer, and a second electrode formed on the second cladding layer; the first and the second cladding layers and the active layer form an optical waveguide in which the light wave propagates.