Abstract: The present invention provides a reflection-type laser projector (100) which projects modulated laser beams outputted from a laser projection unit (40), on a screen, wherein a reflector (112) as a constituent of the screen (110) has reflection characteristics of reflecting, among the incident light, only laser beams of three colors of red, blue, and green, which are projected from the laser projection unit (40) and light in the neighboring wavelength band, and transmitting light in other wavelength band, thereby preventing pictures on the screen (110) from becoming hard to be seen due to effects of indoor illumination or light from outdoors.

Abstract: Laser beams respectively emitted from a SHG blue laser unit and a red semiconductor laser unit that have photo detectors respectively are turned into parallel lights by a collimator lens and then coupled by a dielectric multi-layer film mirror so as to be propagated on the same optical axis. The dielectric multi-layer film mirror is configured so as to transmit light with a wavelength of 500 nm or shorter and reflect light with a wavelength of 500 nm or longer for both P wave and S wave. The lights that are transmitted and reflected by the dielectric multi-layer film mirror pass through a polarizing hologram and a phase variable wave plate and are focused on an optical disk by an objective lens. In this manner, a simple configuration can realize a compatibility with many types of optical disks and a stable signal detection even when using a polarizing optical detection system.

Abstract: A measuring substance (2) is excited by light emitted from a light source (1), fluorescence generated from the substance (2) is directed to transmission-type band-pass filters (4, 6, 8) sequentially, and light having a specific wavelength that has passed through the band-pass filters (4, 6, 8) is detected by light-receiving portions (5, 7, 9). Differences or relative ratios between the signal strengths detected by the respective light-receiving portions (5, 7, 9) are measured to determine a peak wavelength of the fluorescence spectrum, thus identifying the substance (2). With this configuration, a fluorometer can achieve a small size, low cost, and short-time detection.

Abstract: A light source device can attain a stable output of a harmonic even when there occurs a change in the ambient temperature or fluctuation in the output power. The light source device is provided with a semiconductor laser source (4), an optical waveguide-type QPM-SHG device (5) for generating a second harmonic from light emitted from the semiconductor laser source (4), a wavelength control means (7) for controlling a wavelength of light emitted from the semiconductor laser source (4), a means for slightly fluctuating wavelength (8) for changing a wavelength of light emitted from the semiconductor laser source (4) and a means for detecting a change in output light power of the optical waveguide-type QPM-SHG device (5) that occurs when a wavelength of light emitted from the semiconductor laser source (4) is changed.

Abstract: A laser module includes: a sub-mount; a semiconductor laser secured to a surface of the sub-mount; and an optical waveguide device joined to the surface of the sub-mount by an adhesive layer so that the optical waveguide device is coupled optically with the semiconductor laser. A first groove is formed at the surface of the sub-mount at a region corresponding to an incident end side of the optical waveguide device, the first groove being formed parallel to an outgoing end face of the semiconductor laser with a predetermined space therefrom. The adhesive layer is formed so that an end of the adhesive layer on the incident end side of the optical waveguide device is positioned within a range from a position abutting with a distal edge of the first groove distant from the semiconductor laser to an inside of the first groove and does not contact with the outgoing end face of the semiconductor laser.

Abstract: A method for easily and quickly evaluating the wavelength variability properties of a wavelength-variable semiconductor laser is provided. An inspection device includes a power source for supplying current to a wavelength-variable DBR semiconductor laser having an active region, a phase control region, and a DBR region, a photo-detector for detecting an output intensity of laser beam emitted from the wavelength-variable DBR semiconductor laser, and a transmission type wavelength-selection element that can be inserted into a light path from the wavelength-variable DBR semiconductor laser to the photo-detector.

Abstract: An optical information recording/reproducing device reproduces digital data recorded in a form of interference fringes produced by two coherent beams in a hologram disk, by projecting a coherent beam to the hologram disk and receiving a reproduction signal beam obtained by diffraction by means of a two-dimensional photodetector array. The holographic optical information recording/reproducing device includes a tunable coherent light source that emits the coherent beam, and a control section controls and optimizes a wavelength of the tunable coherent light source according to position information of the reproduction signal beam on the two-dimensional photodetector array.

Abstract: After forming domain inverted layers 3 in an LiTaO3 substrate 1, an optical waveguide is formed. By performing low-temperature annealing for the optical wavelength conversion element thus formed, a stable proton exchange layer 8 is formed, where an increase in refractive index generated during high-temperature annealing is lowered, thereby providing a stable optical wavelength conversion element. Thus, the phase-matched wavelength becomes constant, and variation in harmonic wave output is eliminated. Consequently, with respect to an optical wavelength conversion element utilizing a non-linear optical effect, a highly reliable element is provided.

Abstract: A light source of the present invention includes: a semiconductor light emitting device which has a light emitting face and emits light from part of the light emitting face; a container which has a light transmitting window for transmitting the light and accommodates the semiconductor light emitting device; and a gettering portion for performing gettering of a material containing at least one of carbon and silicon. The gettering portion is positioned, in the container, in a region other than the part of the light emitting face of the semiconductor light emitting device.

Abstract: In a short-wavelength laser module, long-term reliability is lost because of unnecessary gas deposited on the end face of its optical waveguide. A short-wavelength laser module has a package structure wherein a package lid used when the short-wavelength laser module is hermetically sealed does not make contact with internal gas, and a process of accelerating the polymerization of a securing agent used inside the package is incorporated, whereby unnecessary gas from the securing agent is eliminated and the long-term reliability of the output is attained.

Abstract: In a Group-III-element nitride semiconductor device including a Group-III-element nitride crystal layer stacked on a Group-III-element nitride crystal substrate, the substrate is produced by allowing nitrogen of nitrogen-containing gas and a Group III element to react with each other to crystallize in a melt (a flux) containing at least one of alkali metal and alkaline-earth metal, and a thin film layer is formed on the substrate and the thin film has a lower diffusion coefficient than that of the substrate with respect to impurities contained in the substrate. The present invention provides a semiconductor device in which alkali metal is prevented from diffusing.

Abstract: Laser beams respectively emitted from a SHG blue laser unit and a red semiconductor laser unit that have photo detectors respectively are turned into parallel lights by a collimator lens and then coupled by a dielectric multi-layer film mirror so as to be propagated on the same optical axis. The dielectric multi-layer film mirror is configured so as to transmit light with a wavelength of 500 nm or shorter and reflect light with a wavelength of 500 nm or longer for both P wave and S wave. The lights that are transmitted and reflected by the dielectric multi-layer film mirror pass through a polarizing hologram and a phase variable wave plate and are focused on an optical disk by an objective lens. In this manner, a simple configuration can realize a compatibility with many types of optical disks and a stable signal detection even when using a polarizing optical detection system.

Abstract: The present invention provides a Group III nitride crystal substrate whose surface has concavities and convexities reduced in size. The surfaces with concavities and convexities, such as hillocks, pits and facets, of Group III nitride crystals are brought into contact with a melt and thereby the surfaces are subjected to meltback etching or mechanochemical polishing. The melt includes at least one of alkali metal and alkaline-earth metal. Thus a Group III nitride crystal substrate that has reduced strain and a reduced number of defects, which are caused through the processing, and is excellent in surface flatness is manufactured. Furthermore, by the use of the Group III nitride crystal substrate of the present invention, for instance, semiconductor devices of high performance can be obtained.

Abstract: The present invention provides a manufacturing method in which high quality GaN crystals and GaN crystal substrates can be manufactured under mild conditions of low pressure and low temperature. In a method of manufacturing GaN crystals in which in a gas atmosphere containing nitrogen, gallium and the nitrogen are allowed to react with each other to generate GaN crystals in a mixed melt of the gallium and sodium, the gallium and the nitrogen are allowed to react with each other under a pressurizing condition that exceeds atmospheric pressure, and pressure P1 (atm (×1.013×105 Pa)) of the pressurizing condition is set so as to satisfy the condition that is expressed by the following conditional expression (I): P?P1<(P+45)??(I), where in the expression (I), P(atm (×1.013×105 Pa)) denotes the minimum pressure that is required for generating GaN crystals at a temperature T°C. of the mixed melt.

Abstract: Laser beams respectively emitted from a SHG blue laser unit and a red semiconductor laser unit that have photo detectors respectively are turned into parallel lights by a collimator lens and then coupled by a dielectric multi-layer film mirror so as to be propagated on the same optical axis. The dielectric multi-layer film mirror is configured so as to transmit light with a wavelength of 500 nm or shorter and reflect light with a wavelength of 500 nm or longer for both P wave and S wave. The lights that are transmitted and reflected by the dielectric multi-layer film mirror pass through a polarizing hologram and a phase variable wave plate and are focused on an optical disk by an objective lens. In this manner, a simple configuration can realize a compatibility with many types of optical disks and a stable signal detection even when using a polarizing optical detection system.

Abstract: In a short-wavelength laser module, long-term reliability is lost because of unnecessary gas deposited on the end face of its optical waveguide. A short-wavelength laser module has a package structure wherein a package lid used when the short-wavelength laser module is hermetically sealed does not make contact with internal gas, and a process of accelerating the polymerization of a securing agent used inside the package is incorporated, whereby unnecessary gas from the securing agent is eliminated and the long-term reliability of the output is attained.

Abstract: The present invention provides a method of manufacturing Group III nitride crystals that are of high quality, are manufactured efficiently, and are useful and usable as a substrate for semiconductor manufacturing processes. A semiconductor layer that is made of a semiconductor and includes crystal-nucleus generation regions at its surface is formed. The semiconductor is expressed by a composition formula of AluGavIn1-u-vN (where 0?u?1, 0?v?1, and u+v?1). Group III nitride crystals then are grown on the semiconductor layer by bringing the crystal-nucleus generation regions of the semiconductor layer into contact with a melt in an atmosphere including nitrogen. The melt contains nitrogen, at least one Group III element selected from the group consisting of gallium, aluminum, and indium, and at least one of alkali metal and alkaline-earth metal.

Abstract: It is an object of the present invention to provide a short-wavelength coherent light source that includes a semiconductor laser and a wavelength converting device and is controlled to have a desired wavelength. The coherent light source includes the following: a semiconductor laser having a first wavelength; an optical waveguide-type QPM-SHG device used as a wavelength converting device for converting the wavelength of the semiconductor laser by half; a wavelength separating function; a diffraction grating; and a photo-detector. The semiconductor laser beam acting as fundamental light is separated with the wavelength separating function, and the wavelength is controlled with the diffraction grating. Thus, the wavelength of harmonic light generated by wavelength conversion is controlled to a desired wavelength.

Abstract: The present invention provides a method of manufacturing Group III nitride crystals that are of high quality, are manufactured highly efficiently, and are useful and usable as a substrate that is used in semiconductor manufacturing processes.

Abstract: The present invention provides a method of manufacturing a gallium nitride single crystal that can suppress the decomposition of gallium nitride and improve production efficiency in a sublimation method. According to the manufacturing method, a material (GaN powder) for the gallium nitride (GaN) single crystal is placed inside a crucible, sublimed or evaporated by heating, and cooled on a substrate surface to return to a solid again, so that the gallium nitride single crystal is grown on the substrate surface. The growth of the single crystal is performed under pressure. The pressure is preferably not less than 5 atm (5×1.013×105 Pa). The single crystal is grown preferably in a mixed gas atmosphere containing NH3 and N2.