Abstract: An optical semiconductor module includes at least one semiconductor chip including at least one laser diode, a sub-mount or a heat sink, on which the at least one semiconductor chip is mounted, and a bonding wire supplying an operating current to the semiconductor chip. The material, diameter, and shape of the bonding wire are selected so that the bonding wire fuses itself when an overcurrent exceeding the operating current of the laser diode is applied.

Abstract: An object is to provide an artificial vision system ensuring a wide field of view without damaging a retina. In the artificial vision system, a plurality of electrodes (23) are to be implanted so as to stick in an optic papilla of an eye of a patient. A signal for stimulation pulse is generated based on an image captured by an image pick up device (11) to be disposed outside a body of the patient. The electrical stimulation signals outputted from the electrodes (23) based on the signals for stimulation pulse stimulate an optic nerve of the eye, thereby enabling the patient to visually recognize the image from the image pickup device (11).

Abstract: A semiconductor laser array device for outputting a higher power includes: a plurality of semiconductor laser chips, arranged in a predetermined pitch; a submount for mounting each semiconductor laser chip; and a heat sink for dissipating heat from the semiconductor laser chip through the submount; wherein a distance S between the centers of the chips and a thickness T of the submount satisfy the following inequality: 2×T?S?10×T, whereby improving efficiency of heat dissipation with a good process yield.

Abstract: An energy dispersal circuit, which generates a PRBS (Pseudo Random Binary Sequence) and executes an XOR (exclusive-OR) operation with respect to a data signal and the PRBS based on a bit, includes a register value calculator for calculating a register value of a shift register based on inputted data and a packet number. The register value calculator has a bit divider for dividing the packet number from LSB to MSB, packet shift operators for bit-shifting an initial value of the shift register from 20 bits to 2N?1 bits, and selectors for selecting inputs and outputs thereof.

Abstract: An Image sensing apparatus employing a multi-chip system and having a super-parallel circuit structure capable of performing processes such as image processing in real time. A first chip of a first of a first stage has first pixel circuits each having an optical sensor and first processing circuits and arranged in a matrix. A second chip of a second stage has second pixel circuits each having an analog memory for storing analog information from the preceding stage and second processing circuits and arranged in a matrix so as to correspond to the first pixel circuits. In each of the first and the second chip, each of the first and the second processing circuits receives an analog signal from another first and second processing circuit in the vicinity so as to perform first and second analog processing and performs circuit noise compensation by parallel calculation.

Abstract: In a diversity receiver comprising an AGC section for controlling the gain of a tuner, an equalizer equalizes an outputted signal from a fast Fourier transformer. A reliability calculator calculates the reliability value of each of carriers by an equalized pilot signal obtained from the equalizer. A reliability value corrector corrects the reliability value by outputted information from the AGC section. A carrier selecting/combining section performs one of selecting and weighting combining for the carrier in a branch in accordance with the corrected reliability value. When a Viterbi decoder is provided, the Viterbi decoder weights an output from the carrier selecting/combining section with a new reliability value to perform maximum likelihood decoding. It is possible to prevent a reliability value which does not reflect an actually received power from being calculated as a result of increasing a power by an AGC in spatial diversity for every OFDM or FDM demodulated carrier.

Abstract: In prior art, when plural frequency selective interferences having different degrees of influences occur, there is a possibility that interference may be unfavorably undetected.

Abstract: A low reflective film is formed of, in sequence from a side in contact with a laser chip, a first dielectric film of a refractive index n1 and a thickness d1, a second dielectric film of a refractive index n2 and a thickness d2, a third dielectric film of a refractive index n3 and a thickness d3, and a fourth dielectric film of a refractive index n4 and a thickness d4, specifically, aluminum oxide Al2O3 with a refractive index n1=1.638 is used for the first dielectric film, silicon oxide SiO2 with a refractive index n2=n4=1.489 for the second and fourth dielectric films, tantalum oxide Ta2O5 with a refractive index n3=2.063 for the third dielectric film, respectively, resulting in a semiconductor laser device with a reflectance which is stably controllable.

Abstract: In fabricating a semiconductor laser 10 with an oscillation wavelength of 770 to 810 nm, impurities are introduced into an MQW active layer 16 near a light emitting facet of the laser to form a disordered region constituting a window layer 20. Pumped light is applied to the window layer 20 to generate photo luminescence whose wavelength &lgr; dpl (nm) is measured. A blue shift amount &lgr; bl (nm) is defined as the difference between the wavelength &lgr; apl (nm) of photo luminescence generated by application of pumped light to the active layer 16 on the one hand, and the wavelength &lgr; dpl (nm) of photo luminescence from the window layer 20 under pumped light irradiation on the other hand. The blue shift amount &lgr; bl is referenced during the fabrication process in order to predict COD levels of semiconductor laser products.

Abstract: A semiconductor laser device includes a stacked structure. The stacked structure includes a first electrode, a substrate of a first conductivity type on the first electrode, a first cladding layer of the first conductivity type, an active layer, a second cladding layer of a second conductivity type opposite the first conductivity type, an insulating layer, and a second electrode. The second cladding layer includes at least first and second portions having thickness different from each other. The first portion is thicker than the second portion. The insulating layer is deposited on the second cladding layer but not on the first portion. The second electrode is electrically connected to the first portion. A product of a reciprocal of layer thickness and heat conductivity of the insulating layer is smaller than 4×108 W/(m2K).

Abstract: The semiconductor laser device includes an active layer, a p-type cladding layer, and a p-type cap layer. The layers are sequentially stacked so that the semiconductor laser device is provided. The p-type cap layer includes both a p-type dopant and an n-type dopant. In another aspect, the p-type cap layer includes a first layer including a first p-type dopant and a second layer including a second p-type dopant having a diffusion coefficient smaller than that of the first p-type dopant. The first layer is far from the active layer, and the second layer is close to the active layer. In further aspect, the p-type cap layer includes carbon (C) as a p-type dopant. According to these configuration, the p-type dopant can be prevented from being diffused in the active layer and the p-type cladding layer.

Abstract: A semiconductor laser device has an n-GaAs substrate (1). On the n-GaAs substrate (1), by turns, an n-AlGaInP clad layer (2), an AlGaInP/GaInP MQW active layer (3), a p-AlGaInP first clad layer (4), a p-AlxGa1-xAs-ESL (5) of a single layer, a p-AlGaInP second clad layer (7) with a stripe-form protrusion (6), and a p-GaAs contact layer (8) are provided. The portion other than the stripe-form protrusion (6) of the p-AlGaInP second clad layer (7) is covered with an insulative film (9). The refractive index of the p-AlxGa1−xAs-ESL (5) is nearly equal to the refractive index of each of the clad layers (2), (4) and (7).

Abstract: A heterojunction structure has an AlxGa1−xAs layer (0<x≦1), on which an AlyGa1−yAs layer (0≦y≦1 and y<x) is provided and having a band gap energy smaller than that of the AlxGa1−xAs layer and a valence band energy edge higher than that of the AlxGa1−xAs layer. When the AlyGa1−yAs layer is selectively etched, an Au electrode film is formed on a surface of the AlyGa1−yAs layer outside an etching region, a resist pattern is formed covering the Au electrode film and leaving exposed the etching region, and the AlyGa1−yAs layer is selectively removed by etching while irradiating with light, using an etching solution having a Fermi level higher than that of the AlyGa1−yAs layer.

Abstract: A semiconductor laser device (10) including a stacked structure. The stacked structure includes a first electrode (6a), a substrate (1) of first conduction type layered on the first electrode, a first cladding layer (2) of the first conduction type, an active layer (3), a second cladding layer (4) of second conduction type opposite to the first one, an insulating layer (5), and a second electrode (6b). The second cladding layer includes at least first and second portion having thickness different from each other. The first portion (8) is thicker than the second portion. The insulating layer is deposited on the second cladding layer except for the first portion. The second electrode is electrically connected to the first portion. In the insulating layer, a product of a reciprocal of a layer thickness and heat conductivity of the insulating layer is smaller than 4×108 W/(m2K).

Abstract: In a semiconductor laser device including a window structure region formed by disordering an active layer or active layers of a quantum well structure by silicon ion implantation and a subsequent heat treatment, a dislocation loop is substantially absent in the window structure region and the vicinity thereof (upper clad layer). Accordingly, deterioration of the semiconductor laser device induced by dislocation loops can be prevented, and reliability of the semiconductor laser device can be improved.

Abstract: In a hetero junction structure having an AlxGa1−x As layer 10 (0<x≦1), on which an AlyGa1−yAs layer (0≦y≦1 and y<x) is provided as having a band gap smaller than that of the AlxGa1−xAs layer 10 and a valence band energy larger than that of the AlxGa1−xAs layer 10, when the AlyGa1−yAs layer is selectively etched, an Au electrode film 16 is formed on a surface of the AlyGa1−yAs layer outside an etching region 14, a resist pattern 18 is formed so as to cover the Au electrode film 16 and expose the etching region 14, and the AlyGa1−yAs layer is selectively removed through the mask of the resist pattern 18 under irradiation of light by use of an etching solution having a Fermi level higher than that of the AlyGa1−yAs layer.

Abstract: In fabricating a semiconductor laser 10 with an oscillation wavelength of 770 to 810 nm, impurities are introduced into an MQW active layer 16 near a light emitting facet of the laser to form a disordered region constituting a window layer 20. Pumped light is applied to the window layer 20 to generate photo luminescence whose wavelength &lgr; dpl (nm) is measured. A blue shift amount &lgr; bl (nm) is defined as the difference between the wavelength &lgr; apl (nm) of photo luminescence generated by application of pumped light to the active layer 16 on the one hand, and the wavelength &lgr; dpl (nm) of photo luminescence from the window layer 20 under pumped light irradiation on the other hand. The blue shift amount &lgr; bl is referenced during the fabrication process in order to predict COD levels of semiconductor laser products.