Abstract: This invention discloses a semiconductor laser capable of a high temperature and high output operation by forming a mesa stripe having an active layer in a reverse triangular mesa shape and forming thick semiconductor layers on both sides of the mesa stripe in such a manner that the resulting p-n junctions have a current blocking function. The invention discloses also a semiconductor laser wherein the formation of the p-n junctions described above is made before the formation of the reverse mesa stripe, and ion implantation is introduced in order to form the p-n junctions. Furthermore, the invention relates to transistors and semiconductor lasers using InGaAsP type quaternary compounds as the semiconductor. The quaternary compounds having a composition in which an energy band gap is from 1.2 to 1.4 eV are formed in a thickness of up to 1 .mu.m, and there can be thus obtained semiconductor devices having a small leakage current and being stable with time.

Abstract: In a semiconductive photodetector device having a semiconductor substrate and a plurality of photodiodes juxtaposed in one major surface of the semiconductor substrate, exposed edges of adjacent pn junctions of adjacent photodiodes are covered with a polysilicon film.

Abstract: Disclosed is means for driving a laser whereby a dc bias current is supplied to keep the laser normally above threshold, and a modulation current brings the laser below threshold when a pulse appears. In one embodiment, a feedback controlled bias current source (11) and modulation current source (15) are coupled to the p-side terminal of the laser (10) while a constant voltage source (27) is coupled to the n-side terminal of the laser in a way which results in subtraction of the modulation current from the dc bias current. This mode of operation essentially eliminates laser overshoot and more nearly equalizes rise and fall times of the light pulses.

Abstract: Room temperature laser action is achieved in a cathode ray tube (CRT) in which the target includes a plurality of semiconductor layers: a thin, wide bandgap buffer layer; a thicker, narrow bandgap active layer; and a much thicker wide bandgap cavity-length-adjusting layer. The light beam direction is essentially parallel to the e-beam direction and hence is scannable.

Abstract: An unstable laser resonator having two spherical mirrors for producing a collimated output beam with rotationally unsymmetrical magnification characterized by the inclusion between the two spherical mirrors of at least two other optical elements with cylindrical surfaces and wherein the cylindrical axes of said cylindrical surfaces are essentially perpendicular to each other. These other two optical elements may be mirrors or lenses.

Abstract: A display electrode for carrying an electrochromic material segment in an electrochromic display device is featured comprising a lead-in electrode for connecting the display electrode to a corresponding driving circuit for coloring the electrochromic material segment, and cut-off portions, not available for any interconnection, for substantially providing a uniform resistance value between the lead-in electrode and every point of the display electrode under the electrochromic material segment.

Abstract: A light emitting semiconductor device having a double hetero junction structure in which oscillation in a single lateral mode is stably effected. A stair-shaped step part is formed in a stripe shape upon the surface of a substrate. A current blocking layer of an opposite conductivity type is formed over the semiconductor substrate with a thickness such that the current blocking layer is interrupted along the upper edge of the stair-shaped step part to form a break area therein which acts as a current concentration region. Over the current blocking layer and break area are formed a lower clad layer, an active layer, an upper clad layer, and an ohmic contact layer.

Abstract: The invention relates to a semiconductor laser with a distributed reflector comprising a semiconductor junction, one of whose semi-transparent mirrors is a split face of the semiconductor in which is integrated a light emitting junction with epitaxial layers. The active layer of this junction is coupled to a waveguide integrated in a dielectric medium, on one face of which is engraved a grating forming a distributed reflector playing the part of the second mirror. The reflector, when functioning according the second order of counter coupling emits a diffracted wave normal to the waveguide which can easily be coupled to an optical fiber.