Abstract: In an exposure device, a beam emitted from a light emitting point of a laser diode (LD) is limited by a slit. The slit limits a light beam in a direction orthogonal to an active layer of the LD. The exposure device has a moving mechanism which moves a plate in which the slit is provided, in a direction orthogonal to the plate. Object points are different at a beam and at flare light. Therefore, the plate is provided in a vicinity of the light emitting point in order to limit the light beam in the vicinity of the light emitting point, i.e., at a place near a point where a beam spot is smallest, and to be able to effectively block only the flare light.

Abstract: When a ratio R between a total angle ? of a widening angle in a median intensity of light of a light source (a GaN based semiconductor laser) and a total angle 2/? of a widening angle of light defining a numerical aperture NA of a collimator optical system (collimator lens) is defined as R=(sin?1NA)×2/?, the numerical aperture of the collimator optical system (collimator lens) is set so that 2.0?R?0.58. Thus, an image exposure device is provided that can suppress stray light of a light source that emits a large amount of stray light.

Abstract: In an exposure system for exposing a color photosensitive body including first, second and third photosensitive materials which respectively develop into cyan, magenta and yellow, the same parts of the photosensitive body are exposed a plurality of times respectively by the first to third linear emitting element arrays. The first to third linear emitting element arrays satisfy conditions Ny<Nm and Nc?Nm, wherein Nc, Nm and Ny respectively represent the numbers of the first to third linear emitting element arrays.

Abstract: In order to obtain a visually high quality image with excellent sharpness using a silver halide photosensitive material, it is necessary to reduce the ratio of EL light in the light output from a GaN based laser diode to 20% or less. For example, when the light intensity measured on a sheet of photosensitive paper is 0.05 mW, the thickness of a waveguide is 3 nm and the width of the waveguide is 3 ?m, this condition is satisfied with a length of a resonator being 1 mm or less. In other words, a waveguide width W1 and a resonator length L are set such that the product of the waveguide width W1 and the resonator length L (W1·L) becomes 0.003 mm2 or less. This reduces the output ratio of the EL light, and a high quality image with excellent sharpness can be obtained when a silver halide photosensitive material is exposed.

Abstract: A transmission apparatus comprises a plastic fiber, and a photodetector for detecting light, which has been propagated through the plastic fiber. The photodetector comprises a plurality of semiconductor light receiving devices, whose light receiving sensitivity wavelength regions are identical with one another, each of the semiconductor light receiving devices having a light receiving area smaller than a cross-sectional area of a core of the plastic fiber. The transmission apparatus is capable of achieving both a high light receiving efficiency and quick response characteristics.

Abstract: In an image exposing apparatus and an image exposing method, a deterioration of an image quality caused by stray light is suppressed, while both a sensitive level and a non-sensitive level are properly set in accordance with a type of photosensitive material. In the image exposing apparatus, a recording level setting unit calculates a recording level corresponding to a light amount level stored in a recording level light amount memory and sets the calculated recording level. A non-recording level setting unit calculates a non-recording level from an extinction ratio, which corresponds to a type of photosensitive material stored in a photosensitive material information memory, and the recording level. An output voltage setting unit sets an output voltage such that a detected voltage becomes equal to one of the recording level and the non-recording level.

Abstract: A fluorescence observing apparatus including a light source for emitting excitation light, an excitation light irradiation section for irradiating the excitation light to a sample, and a fluorescence measurement section for measuring fluorescence emitted from the sample by the irradiation of the excitation light. In the fluorescence observing apparatus, a GaN semiconductor laser is employed as the light source.

Abstract: A GaN system stripe type semiconductor laser having an index guiding structure, and producing higher mode or multimode oscillation in the transverse mode, which is constructed such that the horizontal beam radiation angle of each of a plurality of the emitting regions is minimized to provide a high luminance focused beam. In a GaN system stripe type semiconductor laser, which has an index guiding structure constituted, for example, by a ridge structure formed on a p-GaN cap layer 28 and p-Al0.1Ga0.9N clad layer 27 with the width W2, and produces higher mode or multimode oscillation in the transverse mode, the effective index difference ?n between the central region of the stripe and outside of the stripe is set not greater than 1.5×10?2.

Abstract: In a semiconductor laser element having a plurality of semiconductor layers formed on a substrate, a groove-form concave portion is formed on the surface of the substrate opposite to the surface having the semiconductor layers. The concave portion is filled with metal having a higher heat conductivity higher than the substrate. The semiconductor laser element achieves improved heat dissipation characteristics and high reliability even under high-output operation.

Abstract: When a ratio R between a total angle ? of a widening angle in a median intensity of light of a light source (a GaN based semiconductor laser) and a total angle 2/? of a widening angle of light defining a numerical aperture NA of a collimator optical system (collimator lens) is defined as R=(sin?1NA)×2/?, the numerical aperture of the collimator optical system (collimator lens) is set so that 2.0?R?0.58. Thus, an image exposure device is provided that can suppress stray light of a light source that emits a large amount of stray light.

Abstract: When a ratio R between a total angle ? of a widening angle in a median intensity of light of a light source (a GaN based semiconductor laser) and a total angle 2/? of a widening angle of light defining a numerical aperture NA of a collimator optical system (collimator lens) is defined as R=(sin?1NA)×2/?, the numerical aperture of the collimator optical system (collimator lens) is set so that 2.0?R?0.58. Thus, an image exposure device is provided that can suppress stray light of a light source that emits a large amount of stray light.

Abstract: In an exposure system for exposing a color photosensitive body including first, second and third photosensitive materials which respectively develop into cyan, magenta and yellow, the same parts of the photosensitive body are exposed a plurality of times respectively by the first to third linear emitting element arrays. The first to third linear emitting element arrays satisfy conditions Ny<Nm and Nc?Nm, wherein Nc, Nm and Ny respectively represent the numbers of the first to third linear emitting element arrays.

Abstract: A light source apparatus equipped with a GaN type semiconductor laser, wherein deformation of the shape of the light spot due to fluctuations in the drive current of the light emitting element is prevented, is provided. A light source apparatus equipped with a GaN type semiconductor laser is provided with a slit panel or other spatial filter for eliminating stray light, which amounts to 20% or less of the total output occurring when the GaN type semiconductor laser is driven at maximum output, from the light emitted from the GaN type semiconductor laser.

Abstract: An n-GaN low-temperature buffer layer, an n-GaN buffer layer, an n-In0.05Ga0.95N buffer layer, an n-Al0.15Ga0.85N clad layer, an n-GaN optical guide layer, an undoped active layer, a p-GaN optical guide layer, a p-Al0.15Ga0.85N clad layer, and a p-GaN cap layer, are grown on a sapphire substrate. Then, an epitaxial layer other than a light-emitting region is etched until the n-GaN buffer layer is exposed. Next, in a similar process, etching is performed up to anywhere within the p-Al0.15Ga0.85N clad layer so that a 4-?m-wide stripe region in the form of a ridge remains. The length from the light-emitting facet to the opposite facet is between 30 and 250 ?m.

Abstract: A semiconductor laser module includes: a semiconductor laser element which emits laser light; a waveguide-type optical wavelength selection element which includes an optical waveguide, and selects a first portion of the laser light having a predetermined wavelength; and an optical wavelength conversion element which converts a second portion of the laser light having the predetermined wavelength to wavelength-converted laser light having a converted wavelength. The semiconductor laser element, the waveguide-type optical wavelength selection element, and the optical wavelength conversion element are coupled. The semiconductor laser element contains a multiple-quantum-well active layer including a plurality of quantum-well sublayers, where one of the plurality of quantum-well sublayers is different from another of the plurality of quantum-well sublayers in thickness and/or composition.

Abstract: A semiconductor laser has an active region which includes at least a quantum well layer and upper and lower optical waveguide layers and is of InxGa1?xAsyP1?y (0?x?1, 0?y?1). Upper and lower AlGaAs cladding layers are formed on opposite sides of the active region. At least one of the optical waveguide layers is not smaller than 0.25 ?m in thickness, and a part of the upper cladding layer on the upper optical waveguide layer is selectively removed up to the interface of the upper cladding layer and the upper optical waveguide layer.

Abstract: Light, which has been produced by a semiconductor device and has wavelengths falling within the range of 630 nm to 680 nm, is propagated through a plastic fiber provided with a core containing a polymethyl methacrylate as a principal constituent. The temperature of the semiconductor device is adjusted by a temperature adjusting system comprising a heater for heating the semiconductor device, a temperature detector for detecting the temperature of the semiconductor device and feeding out a temperature detection signal, and a control circuit for controlling actuation of the heater in accordance with the temperature detection signal in order to set the temperature of the semiconductor device at a predetermined target value that is lower than the highest temperature assumed to occur under an environment, in which the semiconductor device is located.

Abstract: In an exposure device, a beam emitted from a light emitting point of a laser diode (LD) is limited by a slit. The slit limits a light beam in a direction orthogonal to an active layer of the LD. The exposure device has a moving mechanism which moves a plate in which the slit is provided, in a direction orthogonal to the plate. Object points are different at a beam and at flare light. Therefore, the plate is provided in a vicinity of the light emitting point in order to limit the light beam in the vicinity of the light emitting point, i.e., at a place near a point where a beam spot is smallest, and to be able to effectively block only the flare light.

Abstract: A surface-emitting semiconductor laser element includes a lower AlGaAs multilayer reflection film, an active layer, a current-confinement layer of a selective-oxidation type or an ion-injection type, and an upper AlGaAs multilayer reflection film which are formed above a GaAs substrate in this order in parallel to a surface from which laser light is emitted. The active layer includes: a quantum well made of InGaAsP having a first forbidden band width; and sublayers arranged adjacent to the quantum well and made of InGaP or InGaAsP which has a second forbidden band width greater than the first forbidden band width. The lower and upper AlGaAs multilayer reflection films constitute an optical resonator. The surface-emitting semiconductor laser element further includes a pair of electrodes which inject current into the active layer.

Abstract: A laser apparatus includes a semiconductor laser element, a surface-emitting semiconductor element including a first mirror, a second mirror, and a modulation unit. The semiconductor laser element emits first laser light having a first wavelength. The surface-emitting semiconductor element is excited with the first laser light, emits second laser light having a second wavelength which is longer than the first wavelength. The first mirror in the surface-emitting semiconductor element is arranged on one side of the first active layer. The second mirror is arranged outside the surface-emitting semiconductor element so that the first and second mirrors form a resonator in which the second laser light resonates. The modulation unit modulates the surface-emitting semiconductor element.