Abstract: The process cartridge includes an electrophotographic photosensitive member having a first support and a photosensitive layer; and a charging member. In the photosensitive member when an electric current is measured which flows when a voltage is applied to a surface while being varied, a gradient a1 of a low electric field region and a gradient a2 of a high electric field region satisfy a2/a1?1.50, in a graph. The charging member includes a second support having an electroconductive outer surface, and a second electroconductive layer including a matrix and a plurality of domains being dispersed in the matrix, at least a portion of the domain is exposed to an outer surface which includes at least the matrix and at least a portion of the domain, and a volume resistivity ?M of the matrix is 1.00×105 times or higher of a volume resistivity ?D of the domain.

Abstract: The process cartridge includes an electrophotographic photosensitive member having a first support and a photosensitive layer; and a charging member. In the photosensitive member when an electric current is measured which flows when a voltage is applied to a surface while being varied, a gradient a1 of a low electric field region and a gradient a2 of a high electric field region satisfy a2/a1?1.50, in a graph. The charging member includes a second support having an electroconductive outer surface, and a second electroconductive layer including a matrix and a plurality of domains being dispersed in the matrix, at least a portion of the domain is exposed to an outer surface which includes at least the matrix and at least a portion of the domain, and a volume resistivity ?M of the matrix is 1.00×105 times or higher of a volume resistivity ?D of the domain.

Abstract: An image sensor includes a pixel array with a plurality of pixels, wherein each of the plurality of pixels includes: a photoelectric conversion unit; and a waveguide structure in which a side face of a substance that has a higher refractive index than a refractive index of a plurality of insulation films is surrounded by the plurality of insulation films so that light is guided to the photoelectric conversion unit, and wherein an insulation film that surrounds a region where the light is concentrated of the side face of the substance has the lowest refractive index among the plurality of insulation films.

Abstract: An image sensor includes a pixel array with a plurality of pixels, wherein each of the plurality of pixels includes: a photoelectric conversion unit; and a waveguide structure in which a side face of a substance that has a higher refractive index than a refractive index of a plurality of insulation films is surrounded by the plurality of insulation films so that light is guided to the photoelectric conversion unit, and wherein an insulation film that surrounds a region where the light is concentrated of the side face of the substance has the lowest refractive index among the plurality of insulation films.

Abstract: An optical semiconductor device includes a substrate and an active region formed on the substrate. The active region includes a plurality of quantum well layers containing at least one tensile-strained well layer, and the plurality of quantum well layers include a plurality of quantum well layers whose band gaps are different from each other. Such an active region makes it possible to expand a wavelength range over which TE-mode and TM-mode gains balance with each other or are approximately equal to each other.

Abstract: An optical semiconductor apparatus includes a substrate, a first region formed on the substrate, a second region formed on the substrate, and a stimulating unit. The first region includes a first waveguide which extends in a light propagation direction and is constructed so as to permit light waves in two different polarization modes to be propagated in the propagation direction. The first waveguide contains a first active region which is constructed such that a gain for one of the different polarization modes is dominant. The second region includes a second waveguide which extends in the propagation direction, is coupled to the first waveguide and is constructed so as to permit light waves in the different polarization modes to be propagated in the propagation direction. The second waveguide contains a second active region which is constructed such that a gain for the other of the different polarization modes is dominant.

Abstract: An optical semiconductor device includes a semiconductor substrate, a first region formed on the substrate and a second region formed on the substrate. The first region has a first active layer, and the second region has a second active layer. At least one of the first active layer and the second active layer contains quantum wires which extend in a cavity direction of the device. The device is constructed such that the first active layer and the second active layer can be stimulated independently from each other.

Abstract: A semiconductor device has a substrate composed of a semiconductor which has one of sphalerite and diamond crystal structures. The substrate has a plane orientation inclined at 0.5.degree. to 15.degree. with respect to one of {111} and {110} planes indicated by Miller indices. A first semiconductor layer is formed on the substrate. The first semiconductor layer has a sawtooth-shaped first periodic structure consisting of one of the {111} and {110} planes indicated by the Miller indices and at least one plane indicated by another index. A second semiconductor layer is formed on the first semiconductor layer. The second semiconductor layer has a second periodic structure having a phase shifted from a phase of the first periodic structure.

Abstract: In a method for producing a compound semiconductor device such as laser devices, FET and HEMT, a crystal layer is formed with materials belonging to at least two (first and second) different groups of the periodic law table under a crystal growth condition under which a value equal to the number of arrival molecules of the material of the first group having a higher vapor pressure divided by the number of arrival molecules of the material of the second group having a lower vapor pressure is equal to or less than 2.5. More preferably, this value is equal to or less than 2.0. More concretely, the crystal layer is made of V/III group elements, for example, As of group V and at least Ga of group III. Under such condition, the crystal layer can be grown with a high quality at relatively low substrate temperatures lower than 500.degree. C.

Abstract: In a method for producing a compound semiconductor device such as laser diodes, FET and HEMT, compound semiconductor is grown at a substrate temperature not greater than 500.degree. C. to form a semiconductor layer on a substrate of the semiconductor device. Then, an appropriate treatment, such as heat-treatment in reducing atmosphere, current flow treatment and hydrogen plasma treatment, is conducted to reduce crystal defects in the semiconductor layer attributable to the crystal growth at the low substrate temperature not greater than 500.degree. C.

Abstract: In a semiconductor laser apparatus of the invention, a semiconductor layer as a substrate on which various semiconductor layers are laminated has a groove or projection having a trapezoidal cross section which extends in the direction of a resonator, and at least one of the semiconductor layers locating on the upstream side of the active layer on a path of a current flowing when a forward bias voltage is applied to electrodes contains p or n type impurity.

Abstract: In a multibeam emitting device provided with a plurality of semiconductive light-emitting elements monolithically formed on a semiconductor substrate, the semiconductor light-emitting elements are formed so that the directions of emission of the lights emitted from the elements differ from one another.

Abstract: A semiconductor laser having a laser resonator structure having a substrate with a trapezoidal projection forming on both sides of an upper base an inclined surface extending along a resonating direction of a resonator, a first semiconductor layer of a first or second conductivity type formed on the substrate, an active layer for generating a laser beam, a second semiconductor layer formed on the substrate and to which an impurity of a convertible conductivity type is doped with a portion of the second semiconductor layer above the inclined surface of the substrate having the first conductivity type and the other portion having the second conductivity type, and a pair of electrodes causing a current to flow through the active layer.

Abstract: A semiconductor laser device wherein a depletion layer is formed in a laser activation layer by biasing the laser device and a third terminal controls an injection current flowing between first and second terminals of the device.

Abstract: A semiconductor laser array includes plural semiconductor laser elements each emitting light from two end faces constituting resonant planes and monolithically formed on a semiconductor substrate, in which the mutual angle of the beams emerging from one end of semiconductor lasers is different from that from the other end and in which the beam angle is selected as a non-zero finite value at least one end.

Abstract: A semiconductor device having a plurality of laminated semiconductor layers in which a current flows in the direction of lamination. A superlattice layer is formed in at least one of the layers and the potential of the quantum well of the superlattice layer is lower than the potential of the semiconductor layer in which the superlattice layer is formed. The potential of the barrier of the superlattice layer is higher than the potential of the semiconductor layer in which said superlattice layer is formed.

Abstract: There is disclosed a semiconductor laser having a super lattice structure near an active layer, in which the super lattice structure consists of at least two types of materials which have different bandgaps, the materials are regularly and alternately arranged, and thickness of adjacent layers of the materials change such that a ratio of the thicknesses changes within the super lattice structure toward an active layer.

Abstract: A semiconductor laser comprises a plurality of lasers provided in the form of an array, the lasers being monolithically formed, a plurality of photodetector elements being monolithically formed, a plurality of first separating portions for separating the lasers and the photodetector elements from each other, and at least one second separating portion for separating the plurality of lasers from one another and the plurality of photodetector elements from one another.

Abstract: A semiconductor device is constructed with a monocrystalline semiconductor layer laminated in a strip-pattern on a substrate, and amorphous or polycrystalline semiconductor layer formed on the substrate in a manner to encompass the monocrystalline semiconductor layers. The monocrystalline semiconductor layer comprises a plurality of layers including a laser active layer.