Abstract: A surface-emission laser diode comprises a cavity region over a semiconductor substrate and includes an active layer containing at least one quantum well active layer producing a laser light and a barrier layer, a spacer layer is provided in the vicinity of the active layer and formed of at least one material, an upper and lower reflectors are provided at a top part and a bottom part of the cavity region, the cavity region and the upper and lower reflectors form a mesa structure over the semiconductor substrate, the upper and lower reflectors being formed of a semiconductor distributed Bragg reflector having a periodic change of refractive index and reflecting incident light by interference of optical waves, at least a part of the semiconductor distributed Bragg reflector is formed of a layer of small refractive index of AlxGa1-xAs (0<x?1) and a layer of large refractive index of AlyGa1-yAs (0?y<x?1), the lower reflector is formed of a first lower reflector having a low-refractive index layer of AlAs an

Abstract: An optical semiconductor device operable in a 0.6 ?m band includes an active layer of GaInNP sandwiched by a pair of GaInP layer with a thickness of about 2 molecular layers or less.

Abstract: A two-dimensional array include N light-emitting arrays each formed of M light-emitting units arranged equally spaced along a direction T tilting from a main scanning direction at an angle ? toward a sub-scanning direction. The light-emitting arrays are equally spaced in the sub-scanning direction. A space ds2 between light-emitting arrays with respect to the sub-scanning direction satisfies ds2=ds1×M where ds1 is a positional difference in the sub-scanning direction between light-emitting units which are adjacent each other in the main scanning direction and orthographically-projected on a virtual line extending in the sub-scanning direction. The angle ? satisfies ?=sin?1((ds2/d1)/M) where d1 is a space between light-emitting units in the light-emitting array with respect to the direction T. The space ds2 is equal to the space d1.

Abstract: A vertical cavity surface emitting laser element is disclosed that includes a substrate, a first semiconductor multilayer reflector including plural pairs of layers having differing refractive indexes and thermal resistances, a resonator region including an active layer, and a second semiconductor multilayer reflector including plural pairs of layers having differing refractive indexes and thermal resistances. At least one pair of layers of the first semiconductor multilayer reflector and/or the second semiconductor multilayer reflector includes a first layer with a lower thermal resistance that has an optical thickness greater than ¼ of the oscillation wavelength and a second layer with a higher thermal resistance that has an optical thickness less than ¼ of the oscillation wavelength. The sum of the optical thickness of the first layer and the optical thickness of the second layer is equal to m/4 times the oscillation wavelength (m: even number?2).

Abstract: A surface-emission laser diode includes a distributed Bragg reflector tuned to wavelength of 1.1 ?m or longer, wherein the distributed Bragg reflector includes an alternate repetition of a low-refractive index layer and a high-refractive index layer, with a heterospike buffer layer having an intermediate refractive index interposed therebetween with a thickness in the range of 5-50 nm.

Abstract: In an optical scanning apparatus, when it is assumed that a scanning direction of light beams defected from a deflector is a main scanning direction, and a direction orthogonal to the main scanning direction and to optical axes of both a first and a second optical systems is a sub scanning direction, a distance between the outermost light emitting diodes of a light source in the main scanning direction is longer than that in the sub scanning direction.

Abstract: A surface-emitting laser device is disclosed that includes a substrate connected to a heat sink; a first reflective layer formed of a semiconductor distributed Bragg reflector on the substrate; a first cavity spacer layer formed in contact with the first reflective layer; an active layer formed in contact with the first cavity spacer layer; a second cavity spacer layer formed in contact with the active layer; and a second reflective layer formed of a semiconductor distributed Bragg reflector in contact with the second cavity spacer layer. The first cavity spacer layer includes a semiconductor material having a thermal conductivity greater than the thermal conductivity of a semiconductor material forming the second cavity spacer layer.

Abstract: A vertical-cavity, surface-emission-type laser diode includes an optical cavity formed of an active region sandwiched by upper and lower reflectors, wherein the lower reflector is formed of a distributed Bragg reflector and a non-optical recombination elimination layer is provided between an active layer in the active region and the lower reflector.

Abstract: A semiconductor light-emitting device has a semiconductor layer containing Al between a substrate and an active layer containing nitrogen, wherein Al and oxygen are removed from a growth chamber before growing said active layer and a concentration of oxygen incorporated into said active layer together with Al is set to a level such that said semiconductor light-emitting device can perform a continuous laser oscillation at room temperature.

Abstract: A semiconductor light emitter includes a quantum well active layer which includes nitrogen and at least one other Group-V element, and barrier layers which are provided alongside the quantum well active layer, wherein the quantum well active layer and the barrier layers together constitute an active layer, wherein the barrier layers are formed of a Group-III-V mixed-crystal semiconductor that includes nitrogen and at least one other Group-V element, a nitrogen composition thereof being smaller than that of the quantum well active layer.

Abstract: The present invention provides, as a pharmaceutical agent having an effect to inhibit the development and/or progression of liver cancer in hepatitis C virus-positive human cirrhosis patients, an agent for inhibiting the development and/or progression of liver cancer in hepatitis C virus-positive human cirrhosis patients, which contains three kinds of amino acids of isoleucine, leucine and valine.

Abstract: A vertical-cavity, surface-emission-type laser diode includes an optical cavity formed of an active region sandwiched by upper and lower reflectors, wherein the lower reflector is formed of a distributed Bragg reflector and a non-optical recombination elimination layer is provided between an active layer in the active region and the lower reflector.

Abstract: A surface-emission laser diode includes a distributed Bragg reflector tuned to wavelength of 1.1 ?m or longer, wherein the distributed Bragg reflector includes an alternate repetition of a low-refractive index layer and a high-refractive index layer, with a heterospike buffer layer having an intermediate refractive index interposed therebetween with a thickness in the range of 5–50 nm.

Abstract: A semiconductor light emitter includes a quantum well active layer which includes nitrogen and at least one other Group-V element, and barrier layers which are provided alongside the quantum well active layer, wherein the quantum well active layer and the barrier layers together constitute an active layer, wherein the barrier layers are formed of a Group-III-V mixed-crystal semiconductor that includes nitrogen and at least one other Group-V element, a nitrogen composition thereof being smaller than that of the quantum well active layer.

Abstract: An optical semiconductor device operable in a 0.6 ?m band includes an active layer of GaInNP sandwiched by a pair of GaInP layer with a thickness of about 2 molecular layers or less.

Abstract: A semiconductor light-emitting device has a semiconductor layer containing Al between a substrate and an active layer containing nitrogen, wherein Al and oxygen are removed from a growth chamber before growing said active layer and a concentration of oxygen incorporated into said active layer together with Al is set to a level such that said semiconductor light-emitting device can perform a continuous laser oscillation at room temperature.

Abstract: A laser diode includes an active layer of a group III-V compound semiconductor device containing N and As as the group V elements. The active layer has exposed lateral edges wherein the N atoms are substituted by the As atoms at the exposed lateral edges by an annealing process conducted in a AsH3 atmosphere.

Abstract: A stationary yoke surrounds an outer peripheral surface of a ring-shaped permanent magnet in a certain distance. The ring-shaped permanent magnet is fixed to a rotor and has two poles of N, S poles in a diameter direction. The stationary yoke includes a first outside yoke and a second outside yoke overlapped in an axial direction and a hole element is disposed in a gap of the first outside yoke. An axial height of the first outside yoke changes along the circumferential direction and a height of the second outside yoke has a complementary relation with the height of the first outside yoke, and the first outside yoke and the second outside yoke are overlapped in a certain clearance.

Abstract: A semiconductor light-emitting device has a semiconductor layer containing Al between a substrate and an active layer containing nitrogen, wherein Al and oxygen are removed from a growth chamber before growing said active layer and a concentration of oxygen incorporated into said active layer together with Al is set to a level such that said semiconductor light-emitting device can perform a continuous laser oscillation at room temperature.

Abstract: A laser diode includes a substrate having a lattice constant of GaAs or between GaAs and GaP, a first cladding layer of AlGaInP formed on the substrate, an active layer of GaInAsP formed on the first cladding layer, an etching stopper layer of GaInP formed on the active layer, a pair of current-blocking regions of AlGaInP formed on the etching stopper layer so as to define a strip region therebetween, an optical waveguide layer of AlGaInP formed on the pair of current-blocking regions so as to cover the etching stopper layer in the stripe region, and a second cladding layer of AlGaInP formed on the optical waveguide layer, wherein the current-blocking regions having an Al content substantially identical with an Al content of the second cladding layer.