Abstract: The light sources according to the present invention include a laser oscillator including a semiconductor laser, a drive circuit for the semiconductor laser, an ACC circuit, an APC circuit, and a switch, and a starting drive current storage device, and is controlled in such a manner that the driving current at the start of the laser driving be always constant, and after the start of the lighting, it is switched to the APC operation to carry out the power control of the laser light output.

Abstract: In the video projector of the present invention, a fiber part of a fiber laser is disposed so as to draw a circulating orbit of more than one circulation along the inner wall of the projector housing. Further, an FBG which is part of the fiber laser is fixed so that its shape is not changed. Furthermore, a pump LD part of the fiber laser is disposed apart from the SHG element. As a result, the video projector can be miniaturized, and the portability and installment of the video projector are facilitated. Further, the output stabilization of the fiber laser can be realized by preventing a shape change of the FBG. Furthermore, by disposing the SHG element apart from the pump LD part which forms a heat source, the temperature change of the SHG element is suppressed and the wavelength conversion efficiency by the SHG element is enhanced.

Abstract: In an onboard gateway apparatus, when data is received from one network, the received data is stored in the buffer. The buffer includes a first storage area for storing data in the order of priority of an identifier (ID) attached to the data and a second storage area for storing data in the order in which the data is received. A control means stores the received data in one of the first and second storage areas based on the attached identifier, and sends the data to another network in accordance with the priority of the ID of the data. As to data passing through the first storage area, sending in the order of priority is ensured. As to data passing through the second storage area, sending in the order in which the data is received is ensured.

Abstract: A holographic optical information recording/reproducing device is provided with a laser light source 1 and a polarizing beam splitter 8 for splitting a light from the laser light source 1. At the time of recording information, one of light beams split by the polarizing beam splitter 8 is modulated by a spatial light modulating element 2 to form a beam array, which becomes a signal light 25, whereas the other split light beam becomes a reference light 22. Interference fringes generated by the signal light 25 and the reference light 22 are recorded as holograms in a holographic disc 5. At the time of reproducing the information, only the reference light 22 is irradiated to the holographic disc 5 and its diffracted light is detected.

Abstract: The present invention provides a planar lighting device (1) including: a laser light source (12) which emits a linearly-polarized laser beam; an optical member (13) which receives the laser beam, then parallelize the laser beam, and emits the parallelized laser beam; and a first plate-shaped light guide (20) which receives the parallelized laser beam from an end face portion (20d) and emits the parallelized laser beam from a first major surface (20b). The first light guide includes an optical element (20a) which receives the linearly-polarized parallelized laser beam propagated through the first light guide and emits at least a part of the linearly-polarized parallelized laser beam in a direction substantially vertical to the first major surface. The present invention also provides a liquid crystal display device (3) using the planar lighting device (1) as a backlight lighting device.

Abstract: Provided are a planar lighting apparatus which can perform display without luminance nonuniformity and with a specified luminance distribution in a scanning direction and has high luminance and a large area, and a liquid crystal display device using such a planar lighting apparatus. The scanning light quantity of scanning light 13 to a light guide section 15 is controlled by a controller 20, so that outgoing light 16 is emitted from a principal surface 17 with a specified luminance distribution in a scanning direction 21 of the scanning light 13.

Abstract: A compact liquid crystal display device is provided by connecting a plurality of liquid crystal display panel units each provided with a light guiding plate unit on a back side with a connection portion and supplying a laser light source via the connection portion. It includes a plurality of display portions formed of liquid crystal display panel units and light guiding plate units disposed in intimate contact with the back sides of the liquid crystal display panel units, a connection portion connecting a plurality of the display portions, and a laser light source. By supplying a laser beam emitted from the laser light source to the light guiding plate units via the connection portion, the display surfaces of the liquid crystal display panel units are illuminated by the laser beam.

Abstract: Disclosed is an arrangement that enables to keep a relative positional relation between a beam for servo control and a beam for information recording/reproduction constant concerning focusing control and tracking control, even if the two beams are different from each other. An optical storage medium has a reflection surface for reflecting a first beam having a first wavelength, and reflecting a second beam having a second wavelength different from the first wavelength; and an information storage layer for recording information as an interference pattern by incidence of the first beam, or reproducing the information from a wave surface based on the interference pattern. The reflection surface is formed with plural marks or guide grooves usable in a tracking operation or a focusing operation by irradiation of the second beam.

Abstract: A wavelength conversion laser 100 is provided with a solid-state laser having a cavity, and a wavelength converting element 6 arranged within the cavity. The solid-state laser includes two or more types of laser crystals 4 and 5 and oscillates solid-state laser light of multiple wavelengths. The wavelength converting element 6 converts the solid-state laser light of multiple wavelengths into light of second harmonic waves and sum-frequency wave of multiple wavelengths and simultaneously generates the second harmonic waves and sum-frequency wave of multiple wavelengths. The wavelength conversion laser 100 outputs converted wavelength light having a broad spectral width and low coherency, thereby enabling it to carry out highly efficient and stable high-output oscillation.

Abstract: A wavelength conversion laser light source includes: a non-linear optical crystal of an oxygen octahedral structure, having added thereto a metal ion in other components than a main component; a light source for projecting light into the non-linear optical crystal in an operation mode; and a refractive index recovery mechanism for carrying out a recovery operation for recovering a refractive index of said non-linear optical crystal as shifted overtime due to light projected into the non-linear optical crystal in the operation mode with an applied external energy into the non-linear optical crystal in a non-operation mode in which light is not injected to the non-linear optical crystal.

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: Since the absorption of a fundamental wave by a fiber increases if it is tried to obtain a wavelength conversion light of watt-class high output, the fiber length needs to be shortened. However, since oscillation efficiency conversely decreases if the fiber length is shortened, it is difficult to obtain a high-output fundamental wave. Thus, by reflecting an excitation light incident on the fiber in the fiber, the excitation light is efficiently absorbed to amplify the fundamental wave with a high gain. Further, by shortening the fiber length, the absorption of the fundamental wave is also reduced to improve a fundamental wave output. Consequently, a wavelength converter capable of ensuring a stable high output up to watt-class is achieved.

Abstract: A wavelength selection substrate 23 is configured with a wavelength selection section 23R which transmits only red laser light and reflects other light components, a wavelength selection section 23G which transmits only a green laser light and reflects other light components, and a wavelength selection section 23B which transmits only a blue laser light and reflects other light components. Of laser light 12 outputted from a light guide plate 14, a laser light component that corresponds to a color passing through one of the wavelength selection sections passes through the wavelength selection substrate 23 and enters a liquid crystal panel 22, whereas a laser light component that does not correspond to the color is reflected from the wavelength selection substrate 23 and returns the light guide plate 14. The laser light having returned the light guide plate 14 is reflected from the reflection plate 21 and again enters the wavelength selection substrate 23.

Abstract: A light projection device, includes a movable projector section which illuminates or display information by projecting light while moving a projection position; a position detecting section which detects a position of a lost article instructed by a user; a view field detecting section which detects a view field of the user, and a controller section which controls said movable projection section based on the lost article detected by the position detecting section and the view field of the user detected by the view field detecting section, and either directly illuminates the lost article or projects guide information for guiding the user to the lost article within a view field of the user.

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 a 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: A fiber laser light source is provided with a laser resonator including a pair of fiber gratings optically connected to a fiber in a state that the fiber is interposed between the paired fiber gratings. The reflection center wavelength of a laser-exit side fiber grating, out of the paired fiber gratings, lies in a wavelength range where the reflectance of a fiber grating, out of the paired fiber gratings, closer to the pump laser light source is not smaller than 80% but not larger than 98%.

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: 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 fiber laser and an optical device for controlling polarization and outputting single polarized light are provided in a simple structure. The fiber laser includes a solid-state laser fiber (3) doped with a rare earth element, a pump light source (1) for exciting the solid-state laser fiber, a reflective element (2) having wavelength dependency, and a wavelength conversion element (4) arranged at the output side of the solid-state laser fiber away from the reflective element at a specified distance along the solid-state laser fiber, in which an end face of the wavelength conversion element (4) is inclined to an optical axis.

Abstract: The present invention concerns a laser light source device capable of multiwavelength oscillation. This laser light source device is provided with a laser light source; a laser cavity including a fiber, a first fiber grating provided at a side of the fiber toward the laser light source and having a plurality of reflection peaks, and a second fiber grating provided at a light emission end of the fiber and having a plurality of reflection peaks; a wavelength converter for converting a fundamental wave emitted from the laser cavity into a harmonic wave; a reflection wavelength varying unit capable of shifting the reflection wavelengths of the reflection peaks of the second fiber grating; and a controller for controlling phase matching conditions of the wavelength converter. Intervals between adjacent reflection peaks of the first fiber grating are different from those between adjacent reflection peaks of the second fiber grating.