Abstract: The present invention provides a hologram recording material which is not required to be subjected to pre-exposure treatment at the time of recording, attains high refractive index change, high sensitivity, low scattering, environment resistance, durability, low dimensional change, and high multiplicity, and is suitable for volume hologram recording. Also, the present invention provides a hologram recording medium. A hologram recording material comprising a matrix material having a softening temperature of 50° C. or higher, and a photopolymerizable monomer which is in a liquid phase state at room temperature. The matrix material is preferably contained in an amount of 50% by weight or more and 90% by weight or less of the whole of the hologram recording material. A softening temperature of the hologram recording material is preferably 0° C. or higher.

Abstract: A wavelength conversion laser light source includes a fundamental wave laser light source (1) to generate a fundamental wave; a first mirror and a second mirror (4, 5), arranged so as to oppose each other; a wavelength conversion element (3) which is arranged between the first mirror and the second mirror and converts the wavelength of the fundamental wave; and a temperature control portion (8) to control the temperature of the wavelength conversion element.

Abstract: A wavelength conversion device includes a laser light source that emits a fundamental wave; a wavelength conversion element that converts the fundamental wave into a second harmonic wave; and an optical system including a wavelength selective mirror that reflects the fundamental wave transmitted through the wavelength conversion element without being converted into the second harmonic wave, while transmitting therethrough the second harmonic wave generated by wavelength conversion, wherein the optical system makes the fundamental wave transmitted through the wavelength conversion element without being converted into the second harmonic wave enter the wavelength conversion element again to be subjected to wavelength conversion once or more than once, while being focused by the wavelength selective mirror, and the conversion efficiency in at least one of the second stage and stages subsequent to the second stage is higher than the conversion efficiency in the first stage, where the conversion efficiency in each

Abstract: A wavelength conversion laser is provided with a solid-state laser having a cavity, and a wavelength converting element arranged within the cavity. The solid-state laser includes two or more types of laser crystals and oscillates solid-state laser light of multiple wavelengths. The wavelength converting element 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 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: An object of the present invention is to provide an optical multiplexing apparatus and a projector that keep an optical system small, and easily adjust a number of light source units. The optical multiplexing apparatus has: a light source section that uses light source units to emit collimated beams; a first lens portion that converges the collimated beams which enter at different incident angles from each other to define converging positions; and a second lens portion that has focal points that correspond to the converging positions, respectively, wherein the first and second lens portions form an optical reduction system, and an optical axis of the second lens portion, which is directed to the corresponding focal point to one of the converging positions, extends along anther optical axis of the second lens position, which is directed to the corresponding focal point to another of the converging positions.

Abstract: Provided are a laser backside irradiation device and a liquid crystal display device reducing a thickness of the respective device and improving a contrast while making a luminance distribution substantially uniform. The laser backside irradiation device includes a laser light source, a splitting optical system splitting laser light emitted from the laser light source into a plurality of laser beams, and a plurality of illumination optical systems illuminating a liquid crystal panel for two-dimensionally modulating a light intensity from a backside thereof, wherein the illumination optical systems expand the laser beams split by the splitting optical system to illuminate divided regions on the liquid crystal panel, respectively.

Abstract: A multipurpose projector is provided with a fiber bundle including a plurality of cores fixedly arranged on an input plane and an output plane, laser beam sources for emitting laser beams having directivities, an optical guide unit for modulating the laser beams emitted from the laser beam sources and guiding the modulated laser beams to the input plane of the fiber bundle, a projection lens for enlarging and projecting the laser beams emerging from the output plane of the fiber bundle to a display space, and a projection angle adjusting mechanism disposed on the side of the output plane of the fiber bundle for adjusting projection angles of the laser beams projected from the projection lens. Thus, the projector can have its projection space freely operated and enlarged to extend its application not only to image display, but also to illumination and decoration with colored light.

Abstract: A wavelength conversion laser light source includes a fundamental wave laser light source; a wavelength conversion element for converting a fundamental wave emitted from the fundamental wave laser light source into a harmonic wave; and an element temperature holding section for holding the wavelength conversion element at a temperature as set, wherein the element temperature holding section includes a magnetic metal formed on at least a part of the surface of the wavelength conversion element via an insulating material, and a magnetic flux application section for heating the magnetic metal with an application of a magnetic flux to the magnetic metal.

Abstract: A GaN-based semiconductor laser (1) emits first laser light of a single polarization and having a first wavelength. An optical resonator (30) includes a solid-state laser medium which is excited by incidence of the laser light and which oscillates second laser light having a second wavelength different from the first wavelength. A polarization switch (6) switches over at least one of polarization directions of the first laser light and the second laser light to thereby change the wavelength of laser light to be emitted from the optical resonator (30) or the intensity ratio between a plurality of laser light to be emitted from the optical resonator (30). With the above arrangement, a plurality of laser light can be used effectively.

Abstract: An image display apparatus having a case supporting laser light source apparatuses emitting laser light of green color, red color, and blue color, a projection optical system; and a cooler that cools the laser light source apparatuses. The case includes: a front wall to which the blue color laser light source apparatus is mounted and a projection outlet of the projection optical system is provided; and a side wall that is connected to the front wall and to which the red color laser light source apparatus and the green color laser light source apparatus are mounted. The cooler is provided on the side wall side. The image display apparatus further includes dichroic mirrors guiding the laser light of respective colors to the projection optical system side. Either of the dichroic mirrors reflects laser light having a wavelength shorter than or equal to the wavelength of the green color laser light.

Abstract: An image display system comprises red, green and blue laser light source units (22 to 24), a spatial light modulator (25) that modulates the laser lights of different colors in a time sharing manner and a control unit (13) for controlling the operation of the laser light source units and the spatial light modulator. The green and red laser light source units are lighted in that order in each frame. The green color is diminished owing to the response delay of the spatial light modulator, but the green laser light produced by the green laser light source unit (23) has a relatively large color phase shift from the standard green color so that the shortage of green color cancels out with the color phase shift of the generated green color so that the color phase shift of the displayed intermediate color can be minimized.

Abstract: There is provided a laser projector, including: a laser source section for emitting laser beams; a spatial light modulator which modulates the laser beams to generate image light; a projector lens from which the image light is emitted; a beam shaper which shapes the laser beams into a shape of the spatial light modulator; and a pupil uniformizer which makes a light intensity distribution uniform at an exit pupil of the projector lens, wherein the pupil uniformizer is situated between the laser source section and the beam shaper.

Abstract: A laser light source includes a semiconductor laser, a wavelength converting element made of a non-linear optical crystal for converting excitation light from the semiconductor laser into wavelength converted light having a wavelength different from the wavelength of the excitation light, a photodiode for measuring a part of the wavelength converted light to be emitted from the wavelength converting element as output light, a photodiode for measuring the excitation light to be emitted from the wavelength converting element, and a control circuit, wherein the control circuit simultaneously performs an output constant control of making the intensity of the wavelength converted light constant, using a current driving circuit, and a temperature control of adjusting the temperature of the wavelength converting element, using a heater.

Abstract: A laser illuminating device and an image display device are provided to enable a removal of speckle noises in a diffraction field and an image field, to uniformly illuminate an illumination plane, and to realize miniaturization. The laser illuminating device 100 includes a laser light source 3 and a first lens 1 including a plurality of microlenses 10, each having a predetermined numerical aperture in an in-plane direction, and each of the microlenses 10 being adapted to expand laser light emitted from the laser light source 3 to thereby superimpose the laser light transmitted through each of the microlenses 10. The laser illuminating device 100 also includes a second lens 2 having an effective diameter larger than an effective diameter of the first lens 1, and compensating for a divergence angle of the laser light expanded by each of the plurality of the microlenses 10.

Abstract: A laser emission device comprises a plurality of laser elements, a plurality of laser driving power supplies, optical elements which uniformize the laser light amount distributions of laser lights, plural light-receiving elements, a measurement unit which measures at least the relations between the operation current values of the laser elements and the output power values of the laser lights with respect to the operation current values, and the control unit operates the laser driving power supplies according to the operation current values and the output power values so as to make the light output powers of the laser elements different from each other.

Abstract: An image display device using a semiconductor laser as a light source, includes a green laser light source device that converts a wavelength of infrared laser light and outputs green laser light; a spatial light modulator that modulates the green laser light input from the green laser light source device based on an image signal; an optical element that is provided in a path between the green laser light source device and the spatial light modulator, and reflects the green laser light to direct it to the spatial light modulator; an optical element support device that supports the optical element; and a case to which the green laser light source device, the spatial light modulator and the optical element support device are attached. The optical element support device rotates about at least one rotation axis in a state of holding the optical element to displace an optical axis of the green laser light.

Abstract: Upon obtaining green light as wavelength converted light by causing infrared light to be incident on a wavelength conversion element, the absorption of the green light occurs due to the generation of ultraviolet light as sum-frequency light of the infrared light and the green light in the wavelength conversion element and the destruction of a crystal composing the wavelength conversion element occurs due to heat generated at this time. In a laser wavelength converter of the present invention, a condensed position of the infrared light in the wavelength conversion element is deviated from a position assumed to be optimal when the influence of the generated heat is ignored. Consequently, crystal destruction is suppressed, a high-efficiency wavelength conversion is enabled and high-output wavelength converted light exceeding several watts, which was difficult to attain in conventional wavelength conversion elements, is attained.

Abstract: A projector for projecting an image light including: a laser light source for emitting a laser beam; a light modulator for modulating the laser beam to generate the image light; a projection portion for projecting the image light; a detector for detecting a fixation degree of the projector; and a controller for controlling the power of the image light on the basis of the fixation degree.

Abstract: A wavelength conversion device includes an excitation light source (11) that generates excitation light, a laser medium (12) that generates fundamental light by means of the excitation light, two resonator mirrors (13) that are disposed with the laser medium (12) being interposed therebetween and resonate the fundamental light, a wavelength conversion element (14) that is disposed between the two resonator mirrors (13) and wavelength-converts the fundamental light to harmonic light, and a drive unit (15) that generates a pulse modulation signal to pulse-drive the excitation light source (11). The laser medium (12) is formed of a material having a thermo-optical effect and a positive thermo-optical constant. The pulse modulation signal generated by the drive unit (15) has an initial interval (P1) including a rising edge of a pulse and a remaining interval (P2) subsequent to the initial interval.

Abstract: A semiconductor laser light source emits a laser beam for pumping. An optical resonator includes a solid laser crystal to be excited by the incident of a laser beam to oscillate a fundamental wave and a pair of fundamental wave reflective coats arranged at the opposite sides of the solid laser crystal. A wavelength conversion element converts the fundamental wave into a plurality of harmonics. The wavelength conversion element is so arranged in the optical resonator that the optical axis of at least one of the plurality of harmonics, generated in the optical resonator is made different from that of the fundamental wave and the at least one harmonic whose optical axis is made different is output substantially in the same direction as the other harmonic. By this construction, it is possible to stabilize a harmonic output and utilize a plurality of harmonics without increasing the number of parts.