Abstract: To provide a nitride semiconductor diode that includes conductive layers formed with a two-dimensional electron gas and achieves low on-state resistance characteristics, a high withstand voltage, and low reverse leakage current characteristics, each of the AlGaN layers and the GaN layers in a nitride semiconductor diode including conductive layers of a two-dimensional electron gas that are formed when the AlGaN layers and the GaN layers are alternately stacked has a double-layer structure formed with an undoped layer (upper layer) and an n-type layer (lower layer).

Abstract: A multi-wavelength light emitting device includes the following three sections; a light source section having multiple luminous points that emit multiple light beams, a condenser lens section that concentrates the light beams emitted from the luminous points, and a light guide section that propagates superposedly and mixedly the light beams concentrated by the condenser lens section after emission thereof from the luminous points.

Abstract: Organic luminescent elements forming an R sub-pixel, a G sub-pixel, and a B sub-pixel are formed of lower electrodes (3, 4, and 5), hole-transporting layers (7, 8, and 11), luminescent layers (9, 12, and 14), electron-transporting layers (10, 13, and 15), and an upper electrode (16), and each of the organic luminescent elements optimizes an optical interference condition. A dielectric alternate laminated film (17) is formed on the upper electrode (16), and forms a micro-resonator with each of the lower electrodes. The micro-resonator structure raises the directivity of a radiation pattern, and improves the light extraction efficiency of each of the organic luminescent elements. A narrow radiation pattern is alleviated by a view angle-controlling layer (19) formed on the dielectric alternate laminated film (17) so as to broaden until a perfectly diffusing surface radiation pattern. Consequently, the light extraction efficiency can be improved in an organic luminescent display device.

Abstract: A living body measuring instrument having a sub-mount on which plural light-emitting devices oscillating at different wavelengths are mounted in proximity, one optical output monitoring device that detects the optical outputs of these light-emitting devices and a light source mounted on the same heat sink which are housed in one can-package, a light-receiving device that detects a signal from a living body, and a circuit that separates the optical output signals from the light-emitting devices, wherein at least one light-emitting device has a light-emitting layer including a In1-xGaxAsyP1-y quantum well layer and a barrier layer on a GaAs substrate, the strain ? satisfies 0.4%???1.4%, wherein y in the composition satisfies 0.10?y?0.45, and the wavelength of the emitted light is from 700 nm to 760 nm.

Abstract: A multi-wavelength light emitting device includes the following three sections; a light source section having multiple luminous points that emit multiple light beams, a condenser lens section that concentrates the light beams emitted from the luminous points, and a light guide section that propagates superposedly and mixedly the light beams concentrated by the condenser lens section after emission thereof from the luminous points.

Abstract: Organic luminescent elements forming an R sub-pixel, a G sub-pixel, and a B sub-pixel are formed of lower electrodes (3, 4, and 5), hole-transporting layers (7, 8, and 11), luminescent layers (9, 12, and 14), electron-transporting layers (10, 13, and 15), and an upper electrode (16), and each of the organic luminescent elements optimizes an optical interference condition. A dielectric alternate laminated film (17) is formed on the upper electrode (16), and forms a micro-resonator with each of the lower electrodes. The micro-resonator structure raises the directivity of a radiation pattern, and improves the light extraction efficiency of each of the organic luminescent elements. A narrow radiation pattern is alleviated by a view angle-controlling layer (19) formed on the dielectric alternate laminated film (17) so as to broaden until a perfectly diffusing surface radiation pattern. Consequently, the light extraction efficiency can be improved in an organic luminescent display device.

Abstract: A super-lattice structure is used for a portion of a laser device of a self-aligned structure to lower the resistance of the device by utilizing the extension of electric current in the layer, paying attention to the fact that the lateral conduction of high density doping in the super-lattice structure is effective for decreasing the resistance of the laser, in order to lower the operation voltage and increase the power in nitride type wide gap semiconductor devices in which crystals with high carrier density are difficult to obtain and the device resistance is high.

Abstract: In a horizontal-cavity vertical-emitting semiconductor laser including an Al-containing semiconductor layer, deterioration of light output property due to oxidization of the Al-containing semiconductor layer is suppressed. A lower cladding layer, an active layer, and an upper cladding layer are stacked in this order from the lower layer on a main surface of a substrate made of GaAs. The upper cladding layer is made of AlGaAs or AlGaInP containing Al in high concentration. An emitting plane layer combining a function of preventing the oxidization of Al contained in the upper cladding layer is formed on an upper portion of the upper cladding layer, and an electric contact layer is formed on an upper portion of the emitting plane layer. The emitting plane layer is made of InGaP, and the electric contact layer is made of GaAs.

Abstract: The present invention provides a Be-based group II-VI semiconductor laser using an InP substrate and having a stacked structure capable of continuous oscillation at a room temperature. A basic structure of a semiconductor laser is constituted by using a Be-containing lattice-matched II-VI semiconductor above an InP substrate. An active laser, an optical guide layer, and a cladding layer are constituted in a double hetero structure having a type I band line-up in order to enhance the injection efficiency of carriers to the active layer. Also, the active layer, the optical guide layer, and the cladding layer, which are capable of enhancing the optical confinement to the active layer, are constituted, and the cladding layer is constituted with bulk crystals.

Abstract: A semiconductor laser device that can be operated at high power and that has a structure which can suppress kink, reduce loss and stabilize the direction of polarization simultaneously, and in which an optical pattern decreases monotonously as receding from an active layer and the crystal composition can be easily controlled. A plurality of layers of high refractive index different in the composition from that of the cladding layer are introduced being dispersed over a range wider than the spot size for directing light closer to the lower cladding layer of the semiconductor laser and stabilizing the direction of polarization. The electric field intensity is decreased monotonously as receding from the active layer for the optical pattern.

Abstract: A living body measuring instrument having a sub-mount on which plural light-emitting devices oscillating at different wavelengths are mounted in proximity, one optical output monitoring device that detects the optical outputs of these light-emitting devices and a light source mounted on the same heat sink which are housed in one can-package, a light-receiving device that detects a signal from a living body, and a circuit that separates the optical output signals from the light-emitting devices, wherein at least one light-emitting device has a light-emitting layer including a In1-xGaxAsyP1-y quantum well layer and a barrier layer on a GaAs substrate, the strain E satisfies 0.4%???1.4%, wherein y in the composition satisfies 0.10?y?0.45, and the wavelength of the emitted light is from 700 nm to 760 nm.

Abstract: The present invention provides a Be-based group II-VI semiconductor laser using an InP substrate and having a stacked structure capable of continuous oscillation at a room temperature. A basic structure of a semiconductor laser is constituted by using a Be-containing lattice-matched II-VI semiconductor above an InP substrate. An active laser, an optical guide layer, and a cladding layer are constituted in a double hetero structure having a type I band line-up in order to enhance the injection efficiency of carriers to the active layer. Also, the active layer, the optical guide layer, and the cladding layer, which are capable of enhancing the optical confinement to the active layer, are constituted, and the cladding layer is constituted with bulk crystals.

Abstract: A super-lattice structure is used for a portion of a laser device of a self-aligned structure to lower the resistance of the device by utilizing the extension of electric current in the layer, paying attention to the fact that the lateral conduction of high density doping in the super-lattice structure is effective for decreasing the resistance of the laser, in order to lower the operation voltage and increase the power in nitride type wide gap semiconductor devices in which crystals with high carrier density are difficult to obtain and the device resistance is high.

Abstract: A semiconductor laser device that can be operated at high power and that has a structure which can suppress kink, reduce loss and stabilize the direction of polarization simultaneously, and in which an optical pattern decreases monotonously as receding from an active layer and the crystal composition can be easily controlled. A plurality of layers of high refractive index different in the composition from that of the cladding layer are introduced being dispersed over a range wider than the spot size for directing light closer to the lower cladding layer of the semiconductor laser and stabilizing the direction of polarization. The electric field intensity is decreased monotonously as receding from the active layer for the optical pattern.

Abstract: An InGaAlAs-based buried type laser is expected to improve properties of the device, but generates defects at a re-growth interface and is difficult to realize a long-term reliability necessary for optical communication, due to inclusion of Al in an active layer. A semiconductor optical device and an optical module including a package substrate and a semiconductor optical device mounted on the package substrate are provided, whereby there are realized the improvement of device properties and the long-term reliability through the use of an Al composition ratio-reduced tensile strained quantum well layer.

Abstract: An InGaAlAs-based buried type laser is expected to improve properties of the device, but generates defects at a regrowth interface and is difficult to realize a long-term reliability necessary for optical communication, due to inclusion of Al in an active layer. The present inventors have studied in detail the relationship between crystals of the regrowth layers and Al composition ratios, and realized the improvement of device properties and the long-term reliability through the use of an Al composition ratio-reduced tensile strained quantum well layer.

Abstract: An information processor of a high reliability and a high recording density, and a blue color, blue-violet color and violet color based semiconductor light emitting device operable at a low threshold current density, used for the same, are provided. An optical information processor of a high reliability and a high recording density enables a moving picture, such as a high-definition television picture, to be recorded and reproduced satisfactorily. A barrier layer in a quantum-well active layer of a semiconductor light emitting device is doped with n-type impurities at a high density. Alternatively, the face orientation of a quantum-well active layer of a semiconductor light emitting device is a plane inclined from the (0001) plane, whereby the threshold current value of the semiconductor light emitting device can be decreased. The semiconductor light emitting device is typified by a gallium nitride based compound semiconductor laser device.

Abstract: The object of disclosing the novel art consists in providing a highly reliable mesa-structured avalanche photo-diode using a novel structure capable of keeping the dark current low, and a fabrication method thereof. The avalanche photo-diode for achieving the object has an absorption layer for absorbing light to generate a carrier, a multiplication layer for multiplying the generated carrier, and a field control layer inserted between the absorption layer and the multiplication layer. Moreover, a first mesa including at least part of the multiplication layer and part of the field control layer is formed over a substrate, a second mesa including another part of the field control layer and the absorption layer is formed over the first mesa, the area of the top surface of the first mesa is greater than that of the bottom surface of the second mesa, and a semiconductor layer is formed over the part of the first mesa top surface not covered by the second mesa and the side surface of the second mesa.

Abstract: Provided are highly reliable information processing equipment enabling a high recording density, and a blue color, blue-violet color and violet color based semiconductor light emitting device operable at a low threshold current density, which device is suitable for the information processing equipment. According to the present invention, there can be realized highly reliable optical information processing equipment enabling high recording density, which is capable of sufficiently recording or reproducing a dynamic image in or from a high-definition TV. An n-type impurity is doped in a barrier layer of a quantum-well active layer of a semiconductor light emitting device at a high density. Alternatively, the oriented plane of a quantum-well active layer of a semiconductor light emitting device is inclined from the (0001) plane, whereby the threshold current value of the semiconductor light emitting device can be reduced.

Abstract: The object of disclosing the novel art consists in providing a highly reliable mesa-structured avalanche photo-diode using a novel structure capable of keeping the dark current low, and a fabrication method thereof. The avalanche photo-diode for achieving the object has an absorption layer for absorbing light to generate a carrier, a multiplication layer for multiplying the generated carrier, and a field control layer inserted between the absorption layer and the multiplication layer. Moreover, a first mesa including at least part of the multiplication layer and part of the field control layer is formed over a substrate, a second mesa including another part of the field control layer and the absorption layer is formed over the first mesa, the area of the top surface of the first mesa is greater than that of the bottom surface of the second mesa, and a semiconductor layer is formed over the part of the first mesa top surface not covered by the second mesa and the side surface of the second mesa.