Abstract: In an optical pickup apparatus, a laser beam emitted from a semiconductor laser device is reflected upward by a reflecting member, transmitted through a transmission type diffraction grating and split into at least three beams, and which beams are transmitted through a transmission type holographic optical element and condensed onto an optical recording medium by a condenser portion. A return beam reflected by the optical recording medium passes through the condenser portion and diffracted not to impinge upon the transmission type diffraction grating by the holographic optical element and directed to a photodetector portion of a light receiving device. The semiconductor laser device and the light receiving device are disposed in a mount member.

Abstract: A light emitting diode device comprises an n type silicon carbide substrate having first and second major surfaces opposite to each other at least inclined at a predetermined angle not less than 3.degree. from a {0001} plane, an n type silicon carbide layer grown on the first major surface, a p type silicon carbide layer grown on the n type silicon carbide layer, a p type ohmic electrode formed on a partial area of the p type silicon carbide layer, and an n type ohmic electrode formed on a partial area of the second major surface. The diode element has a substantially trapezoidal form in a cross section orthogonal to the first major surface. The diode element has the side of the p type silicon carbide layer broader than the side of the second major surface and is supported at the side of the type silicon carbide layer fixed to a supporting stem.

Abstract: A semiconductor laser includes an oscillation layer comprising a first clad layer, an active layer and a second clad layer which are comprised of gallium aluminum arsenide and deposited, in this order, on a semiconductor substrate. A buried cap layer in a stripe geometry for narrowing a width of a current path is deposited on a second clad layer. A burying layer comprised of II-VI compound such as zinc selenide, zinc sulfide and the like is formed on the second clad layer other than the portion on which the cap layer is formed, so that the cap layer is buried. The buried layer is formed utilizing a low temperature deposition such as a molecular beam epitaxy.