Abstract: An illumination light source is provided with a laser light source having a laser medium with a specified gain region, and a reflector having a narrow band reflection characteristic. A part of a laser light emitted from the laser light source is reflected and fed back by the reflector, so that an oscillation wavelength of the laser light source is fixed at a reflection wavelength. A peak of the gain region of the laser medium is shifted from the reflection wavelength by a change of an oscillation characteristic of the laser light source, so that the oscillation wavelength of the laser light source is changed from the reflection wavelength. Thus, an oscillation spectrum of the laser light source is spread to reduce speckle noise.

Abstract: The present invention comprises: a laser light source 101 operable to output a laser light; an optical component 114 operable to couple, to an optical fiber 126, the laser light outputted from the laser light source 101; an actuator 118 operable to hold the optical component 114; a photoreceiver 503 operable to monitor the laser light outputted from the optical fiber; and a control device 117 operable to drive the actuator 118 in accordance with a result of the monitoring by the photoreceiver 503, thereby controlling a position of the optical component 114.

Abstract: A display device (100) of the present invention has a first switch (3) and a second switch (4) on an upper surface of its casing, and includes a control circuit (18) for controlling the first switch (3) and the second switch (4) and a light source (19) inside the casing. The control circuit (18) performs control so that the light source (19) is turned on when the second switch (4) is pressed after a predetermined period of time has passed from when the first switch (3) was pressed. Thereby, the display device (100) of the present invention prevents entering of a person into a projection area before projection of video, and controls inadvertent start-up.

Abstract: In a method of attaching an electronic component to a printed circuit board by a plurality of screws that are inserted into corresponding through holes cut in the board from a surface of the board and then screwed into corresponding screw holes formed in the component mounted on an opposite surface, the component is screwed onto the board using one of the screws and the component and the screw are soldered onto the board with lead-free solder. After they have been cooled down, the component is screwed onto the board using remaining screws. With this, the strength of the connection between the component and board is improved and also the occurrence of warp of the board and component can be prevented.

Abstract: Efficient coupling structures are important for the realization of reliable and economical integrated optical circuit applications. This paper presents a new approach for the simulation of an anisotropic plasma etching process in silicon based on a string point model as well as the realization and the results of etching processes in silicon, silicon dioxide, silicon oxinitride and silicon nitride which are fundamental for the fabrication of coupling structures. The connections to active and passive components were fabricated using plasma etching and deposition processes which are compatible with C-MOS or BIC-MOS technology. The realized waveguide-detector structures with vertical and horizontal silicon PIN-diodes exhibit efficiencies close to 90% for wavelength below 1.1 micrometers. The diodes can detect signals of modulation frequencies of more than 400 MHz due to horizontal light injection and capacitances less than 1 pF.

Abstract: There are provided a reflection type screen capable of suppressing effects of external light and obtaining a wide viewing angle with a simple structure, and a forward projection system having the reflection type screen. A reflection type screen 100 has transparent prismatic members 5 arranged parallel to a longitudinal direction of a base 1, between the base 1 of a light absorbing member and a front sheet 2 of a transparent projective layer. Each transparent prismatic member 5 has a transmissive plane 3, and a diffusion-reflection plane 4 formed at a specified angle. The diffusion-reflection plane 4 is formed by arranging a reflection film on one of surfaces of the transparent prismatic member 5. Projection light is diffused and reflected by the diffusion-reflection plane 4, and external light passes through the transmissive plane 3, and is absorbed in the base 1.

Abstract: A short wavelength light source of the present invention comprises a nonlinear crystal having a periodical polarization reversal structure. The polarization reversal structure of the nonlinear crystal is divided into a plurality of regions and the polarization reversal structure and the optical axis of the fundamental wave are inclined with different angles in the respective regions, so that higher harmonic generated is divided into a plurality of beams. By dividing the higher harmonic component into a plurality of beams, it is possible to reduce the power density of the higher harmonic and generate walk off in the fundamental wave and the higher harmonic, thereby to suppress generation of the sum frequency waves of the fundamental wave and the higher harmonic so as to enhance the tolerance to high output. Therefore, SFG generation is suppressed, and a high output power coherent light source is realized.

Abstract: A thin planar illumination device with a high light utilization efficiency is provided. In a planar illumination device 10, light source sections 15, 16, 17 and 18 each radiates laser light. The light guide members 19 and 20 polarize, by total reflection, light incident from side surfaces 19b and 20b on two opposite sides thereof, so as to be radiated from incident surfaces 19a and 20a, respectively. In a light guide plate 21, the light is incident from side surfaces beside the respective light guide members 19 and 20 so as to radiate irradiation light 24 from main surfaces 21a and 21b. The main surface of the light guide plate 21 is formed by a plurality of inclined surfaces, each being gradually thinned from the edge surfaces on two sides thereof toward a center thereof.

Abstract: A wavelength converting element which does not generate crystal destruction and output saturation of a second harmonic due to a third harmonic generated inside the element is provided. The wavelength converting element receives a fundamental wave which is light having a wavelength (lambda), outputs the second harmonic which is light having a wavelength (lambda/2), and has a crystal including at least one element selected from a group composed of Sc, Y, La, Ce, Pr, Eu, Gd, Ho, Yb, and Lu as an additive.

Abstract: An optical fiber 13, of which one end 13a is optically coupled to a laser light source 12, for propagating, from the one end 13a to other end 13c, a laser light emitted from the laser light source 12, and a light-guiding plate 11 including a light-guiding section 11b in which a plurality of right prisms of the same shape for extracting the laser light by contacting the optical fiber 13 are arranged parallel to each other in the same direction at equal intervals, and also including a planar section 11c for diffusing the laser light extracted from the light-guiding section 11b and emitting the diffused laser light from one main surface, are provided. The optical fiber 13 is bent more than twice to form a plurality of straight line portions arranged parallel to each other at unequal intervals, and the optical fiber 13 and the light-guiding plate 11 are positioned such that the laser light is extracted at equal intervals from each of the plurality of straight line portions.

Abstract: In a semiconductor laser device (10) having different facet reflectivities, an electrode disposed on a stripe ridge (107a) is divided into four electrode parts (1), (2), (3), and (4), and a larger injection current is injected to an electrode part that is closer to a light emission facet side. Further, a carrier density distribution in an active layer that is opposed to the stripe ridge can be matched to a light intensity distribution in the active layer, thereby preventing degradation in high output characteristic due to destabilization of a transverse mode and reduction in gain which are caused by spatial hole burning.

Abstract: A regeneration control system which permits highly efficient regeneration while a vehicle is traveling stably, and also permits regeneration to be performed without interfering with a smooth behavior correction made by a driver when the behavior of the vehicle has been disturbed. The regeneration control system includes a total regeneration amount determiner for determining the total regeneration amount of a first electric motor connected to front wheels and a second electric motor connected to rear wheels, a regeneration amount allocation determiner for determining regeneration amount allocation to each electric motor, a determination value calculator for calculating a determination value based on a steering angle and a yaw rate, and a determiner for determining whether a determination value lies within a predetermined range.

Abstract: An image display device and an image display system which can establish visible light communication without interfering with an image displayed at a predetermined frame rate are provided. A controller 12 controls a spatial light modulator in accordance with an image signal to display the image, and also modulates an intensity of a visible light output from a backlight 13 with a frequency higher than the frame rate of the image signal to have the visible light output from the backlight 13 carry additional information. A light receiver 15 receives the visible light and demodulates to extract the additional information. An additional information generator 16 outputs the additional information.

Abstract: A short wavelength light source is provided with a fundamental wave light source for generating a fundamental wave, and a plurality of wavelength conversion elements made of nonlinear optical crystals having periodic polarization-inversion structures and adapted to convert a part of the fundamental wave into a second harmonic, and the nonlinear optical crystals of the plurality of wavelength conversion elements are different in material or composition. By converting the fundamental wave from the fundamental wave light source by the plurality of wavelength conversion elements, the generation of a thermal lens effect caused by light absorption can be suppressed to improve a high output resistance.

Abstract: Light emitted from a wide stripe semiconductor laser with increased output and efficiency is passed through a mode converter and a wavelength selecting filter, then fed back to the active layer of the semiconductor laser, which fixes the oscillation mode of the semiconductor laser to single mode, making lateral-mode control possible.

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: In a laser picture formation device which forms a vide image by irradiating lights emitted from plural laser light sources (1a, 1b, 1c) which obtains monochromatic lights from laser lights which are outputted from the respective laser light emission parts to spatial light modulators (5a, 5b, 5c), each of the plural laser light sources (1a, 1b, 1c) detect the output of laser light which is emitted from the respective laser light emission parts on the basis of the modulation input signal which for modulating the spatial light modulator. Thereby, it is possible to confirm the deterioration situation of the respective laser light emission parts without deteriorating the video images which are projected onto the screen, as well as without separating the synthesized light respectively.

Abstract: A surface illumination device is provided with a laser light source capable of emitting a laser light, an incident surface on which the laser light is incident, a light guiding plate having a principal surface from which the laser light emerges as a surface emergent light, and an irradiating member capable of irradiating the laser light from the laser light source over a specified range extending in the longitudinal direction of the light guiding plate.

Abstract: A surface illumination apparatus includes: a light source; an end-surface light-guide portion which guides light emitted from the light source in a long-side direction thereof and generates emitted light in a short-side direction thereof; and a light guide plate which allows the emitted light to be incident upon an end-surface portion thereof and emits the incident light from one main-surface portion thereof. The end-surface light-guide portion includes a plurality of polarization control portions arranged in the long-side direction; the plurality of polarization control portions each has a half-wave plate and a polarizing prism; the end-surface light-guide portion emits the emitted light in the form of either of S-polarized light and P-polarized light, using the plurality of polarization control portions; and the light guide plate emits, as output light, either of S-polarized light and P-polarized light from the one main-surface portion.

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.