Abstract: An optical transmission and receiving module includes a light source; a light receiving element; and a light branching element for causing signal light from the light source to be incident on an optical fiber and causing signal light output from the optical fiber to be incident on the light receiving element. The light branching element includes a prism array including a plurality of triangular prisms arranged at substantially an identical pitch on a plane extending substantially perpendicular to an imaginary line connecting the light source and the light receiving element.

Abstract: The invention provides a semiconductor light emitting device in which a light emitting layer is formed on a semiconductor substrate in a state of lattice mismatching with this semiconductor substrate, and by which light emission of high efficiency is obtained. A semiconductor material used as a base material of the light emitting layer is doped with impurities serving as radiative recombination centers. The semiconductor substrate is a GaP substrate and the semiconductor material as the base material of the light emitting layer is (Al.sub.x Ga.sub.1-x).sub.1-y In.sub.y P. This (Al.sub.x Ga.sub.1-x).sub.1-y In.sub.y P material is doped with nitrogen, oxygen, selenium, sulfur or tellurium as a first impurity for forming a donor level, and also with magnesium, zinc or cadmium as a second impurity for forming an acceptor level.

Abstract: On a first cladding layer formed of n-type Al.sub.0.7 Ga.sub.0.3 P, an active region having a staggered-type (type II) heterojunction superlattice structure is disposed. The active region includes 50 light emitting layers formed of Al.sub.0.1 Ga.sub.0.9 P doped with nitrogen and 50 barrier layers formed of Al.sub.0.7 Ga.sub.0.3 P. The 50 light emitting layers and the 50 barrier layers formed of such materials are stacked alternately to form 50 pairs. On the active region, a second cladding layer formed of Al.sub.0.1 Ga.sub.0.9 P is disposed. In the formation of the active layers the composition of the light emitting layer and the barrier layer end the thickness of the barrier layer are controlled so that the isoelectronic level in the light emitting layer and the quantum level in the barrier layer will fulfill the resonance conditions.

Abstract: A semiconductor structure including: a substrate having a step portion; a first semiconductor layer formed on a region of the substrate which is selectively irradiated by light at an angle with respect to the projecting portion by using the step portion as a mask; and a second semiconductor layer formed on a region of the substrate shaded by the step portion.

Abstract: A semiconductor light emitting device includes: a compound semiconductor substrate of a first conductive type; a multilayer structure formed on the compound semiconductor substrate, the multilayer structure including at least an active layer for emitting light, a lower cladding layer of the first conductive type and an upper cladding layer of a second conductive type with the active layer interposed therebetween; an intermediate layer of the second conductive type formed on the multilayer structure; and a current diffusion layer of the second conductive type formed on the intermediate layer. The intermediate layer alleviates at least one of a lattice mismatching between the upper cladding layer and the current diffusion layer and a difference in energy positions at a lower end of a conduction band and/or an upper end of a valence band in an energy band profile which is exhibited before forming a junction between the upper cladding layer and the current diffusion layer.

Abstract: On a first cladding layer formed of n-type Al.sub.0.7 Ga.sub.0.3 P, an active region having a staggered-type (type II) heterojunction superlattice structure is disposed. The active region includes 50 light emitting layers formed of Al.sub.0.1 Ga.sub.0.9 P doped with nitrogen and 50 barrier layers formed of Al.sub.0.7 Ga.sub.0.3 P. The 50 light emitting layers and the 50 barrier layers formed of such materials are stacked alternately to form 50 pairs. On the active region, a second cladding layer formed of Al.sub.0.1 Ga.sub.0.9 P is disposed. In the formation of the active layer, the composition of the light emitting layer and the barrier layer and the thickness of the barrier layer are controlled so that the isoelectronic level in the light emitting layer and the quantum level in the barrier layer will fulfill the resonance conditions.

Abstract: A semiconductor structure including: a substrate having a step portion; a first semiconductor layer formed on a region of the substrate which is selectively irradiated by light at an angle with respect to the projecting portion by using the step portion as a mask; and a second semiconductor layer formed on a region of the substrate shaded by the step portion.

Abstract: A semiconductor light emitting device which allows part of an active layer to generate light by supplying current to the part of the active layer is disclosed. The semiconductor light emitting device includes: a semiconductor substrate having upper and lower surfaces, the upper surface having a stepped portion, the stepped portion dividing the upper surface into at least a first area and a second area; a current confining layer, formed on the upper surface of the substrate, the current confining layer being discontinuous at the stepped portion, the current flowing through an area between the first area and the second area of the substrate; a multilayer structure formed on the current confining layer, the multilayer structure including the active layer; a first electrode which covers only part of an upper surface of the multilayer structure; and a second electrode formed over the lower surface of the substrate.

Abstract: A surface electrode on a surface of a LED has a pad, and further, at least first-order branches linearly extending from the pad, second-order branches diverged and linearly extending from the first-order branches, and third-order branches diverged and linearly extending from the second-order branches. The pad out of the surface electrode is not in electrical contact with a underlying semiconductor layer, whereas the surface electrode and the semiconductor layer are in electrical contact with each other at ends of the highest-order branches. Also, the semiconductor layer is provided along a pattern of the surface electrode in a mesa shape. Thus, ineffective light emission underneath the surface electrode is relatively reduced so that external quantum efficiency can be improved, and moreover even shorter-wavelength light can be allowed to go out at high efficiency by omitting a current diffusion layer.

Abstract: A semiconductor laser device is provided which is constituted by semiconductor materials so as to emit laser light from a cavity end facet, the laser light being excited in a waveguide within an active layer sandwiched between a pair of cladding layers, wherein a window layer made of a semiconductor material having a band gap greater than that of the active layer is formed on the cavity end facet from which the laser light is emitted, so as to have a thickness sufficient to prevent local generation of crystal defects by lattice mismatching between the semiconductor material of the window layer and the semiconductor materials at the cavity end facet. There is also provided a method for producing such a semiconductor laser device with high efficiency.

Abstract: An optical coupling circuit element providing one transparent substrate, a first micro Fresnel lens formed on one side surface of said substrate, and a second micro Fresnel lens formed on the other side surface of said substrate, so that coherent light incident into said first micro Fresnel lens is projected, through said transparent substrate, on said second micro Fresnel lens to be left therefrom as a collimating beams, which is useful for directing light emitted from coherent source such as semi-conductor laser to optical communication means such as optical fiber for condensation.

Abstract: A socket for a semiconductor device comprises receiving holes to which lead pins of the semiconductor device are inserted, and conductive coupling portions for connecting the receiving holes and conductive portions of a circuit board. The socket is placed on a circuit board and the conductive coupling portions are connected to the conductive portions of the circuit board to be mounted. The lead pin receiving holes of the socket are formed to be parallel to the surface of the circuit board when the socket is mounted on the circuit board.