Abstract: A one-dimensional transverse multiple mode laser is used for a one-dimensional illumination apparatus. A pumping light source, and a laser medium and a wavelength conversion device (nonlinear optical crystal or a nonlinear optical device) which are disposed in a resonator, are provided, and the nonlinear optical crystal or a nonlinear optical device is irradiated with a line beam obtained by exciting the laser medium in an elliptic transverse mode pattern. Then, a one-dimensional light modulation device is irradiated with the wavelength-converted line beam, and scanning with the beam modulated by the modulation device is conducted to produce a two-dimensional image.

Abstract: A photonic crystal fiber has a configuration in which a multiplicity of voids are arranged along the longitudinal direction of the fiber and with a regular sectional structure, a terminal end portion of the fiber is fusion bond sealed with a fusing material composed of a glass lower than a light propagation medium of the fiber in softening temperature, and the terminal end portion is connected to a ferrule with the fusing material. With this configuration, it is possible to obviate the lowerings in optical characteristics such as a large refractive index difference between the light propagation medium and the voids, a high light transmission efficiency, a high numerical aperture, etc., and to obviate such problems as the penetration of foreign matter into the inside of the voids, a burning failure arising from a positional staggering of the ferrule, etc.

Abstract: Speckle noise is reduced to increase image quality in an image display apparatus such as a projection display or the like.

Abstract: A laser apparatus includes a master laser for emitting reference laser pulse light RPref having a wavelength of 914 nm and a pulse width of 0.5 ns; a microlens array for dividing the reference laser pulse light RPref into N pieces of light; optical fiber amplifiers 14-1 to 14-N being set to increase their length progressively in that order so as to have a propagation delay time of 0.5 ns, which is the pulse width of the divided pieces of reference laser pulse light DRPref1 to DRPrefN; a third harmonic generating unit for receiving the divided pieces of reference laser pulse light on which amplifying and delaying effects have been produced, and generating third harmonics TRD1 to TRDN having a wavelength of 305 nm and a pulse width of 0.5 ns; and an illuminating optical system for successively disposing the N third harmonics TRD1 to TRDN in parallel with each other, subjecting the N third harmonics TRD1 to TRDN to time multiplexing, and emitting the result.

Abstract: An image display unit includes a linear display device. The linear display device is line-scanned to display a two-dimensional image. The linear display device has a video signal protection function. In the linear display device, video protection can be implemented using a very simple system for turning off some pixels. Device ID information can be embedded into a display terminal using the image display unit.

Abstract: An ultraviolet optical device includes optical parts on which an ultraviolet ray is irradiated. Some or all of the optical parts are arranged in an envelope having a gas inlet port and a gas output port. In the envelope (9), a dry gas having an amount of moisture (as volume fraction) of 5,000 [ppm] or less and led from the gas inlet port (10) is sprayed on an optical part in which at least a deterioration in optical characteristics is especially a problem, so that an improvement in the secular change of the optical part can be achieved.

Abstract: A laser apparatus includes a master laser for emitting reference laser pulse light RPref having a wavelength of 914 nm and a pulse width of 0.5 ns; a microlens array for dividing the reference laser pulse light RPref into N pieces of light; optical fiber amplifiers 14-1 to 14-N being set to increase their length progressively in that order so as to have a propagation delay time of 0.5 ns, which is the pulse width of the divided pieces of reference laser pulse light DRPref1 to DRPrefN; a third harmonic generating unit for receiving the divided pieces of reference laser pulse light on which amplifying and delaying effects have been produced, and generating third harmonics TRD1 to TRDN having a wavelength of 305 nm and a pulse width of 0.5 ns; and an illuminating optical system for successively disposing the N third harmonics TRD1 to TRDN in parallel with each other, subjecting the N third harmonics TRD1 to TRDN to time multiplexing, and emitting the result.

Abstract: A laser beam in the ultraviolet region is generated at high power for along period. A green laser beam generated by a laser oscillator comes incident into a resonator from behind a first curved mirror, and circulates there, reflected by each mirror. By passing a barium borate crystal, it causes a secondary harmonic (a laser beam in the ultraviolet region) to be generated, which is taken out of the resonator via a second curved mirror. The beam waist of the laser beam passing the barium borate crystal is set to 46 &mgr;m, about double the conventional thickness, by adjusting the distance between the first curved mirror and a second flat mirror. As a result, the power density of the laser beam in the barium borate crystal is reduced to ¼ of the value according to the related art, and it is made possible to avoid rapid degradation of the barium borate crystal by excessive squeezing of the laser beam.

Abstract: A measurement method and a measurement apparatus for measuring the structure of a micro-structure or the structure along the depth of an object for measurement. The laser light from a solid-state laser light source is subjected to wavelength conversion to generate the ultraviolet laser light, and measurement is made of the object for measurement by heterodyne detection or homodyne detection employing the ultraviolet laser light. This enables measurement of a structure of a micro-structure. Alternatively, the laser light is split into multiple laser light beams and frequency shifted so that the laser light beams will be of different frequencies. The laser light beams are imaged at respective different focal point positions to perform heterodyne detection. The resulting heterodyne signals are separated into respective frequency bands and measurement is made of the structure of the object for measurement in association with the respective imaging points.

Abstract: Disclosed herein is an external resonant laser that comprises a laser oscillator and an external resonator. The laser oscillator emits a laser beam of a specific wavelength. The external resonator resonates the laser beam emitted from the laser oscillator. The external resonator contains a photopolymer volume hologram. The photopolymer volume hologram diffracts the laser beam emitted from the laser oscillator, applies the laser beam into an optical system provided in the external resonator and allows the passage of a laser beam of a prescribed wavelength. The laser beam of the prescribed wavelength is output from the external resonant laser.

Abstract: In an optical system having at least one optical part other than mirrors, for example, a wavelength conversion optical system which uses an external resonator, an optical system which is capable of solving the problem of transverse mode generation due to the existence of scattering matter and the optical crystal used and capable of supplying a stable output (stable wavelength conversion output) is provided. At least at one point in a stable resonator having optical parts (optical crystal) other than mirrors, an aperture having a circular hole with a diameter 1 to 10 times the diameter of a beam at the aperture, a slit having a width 1 to 10 times the diameter of the beam, or an aperture of an arbitrary shape having an edge is located, or a knife edge having an linear or curved edge is Located so that the nearest distance between the edge and the beam is 1 to 10 times the radius of the beam from the center of the beam.

Abstract: A laser light source unit generates second higher-harmonic waves or sum-frequency waves by using an external resonator. The light source unit has a wavelength converter which incorporates an external resonator. A modulator spatially modulates the output light from the converter, thereby removing speckle noise. An optical waveguide propagates the laser light from the modulator to a given optical apparatus. The wavelength converter, the modulator, and the optical waveguide are mechanically separated. Moreover, vibration isolating members are provided to inhibit vibrations. Thus, any change in the length of the resonator or the optical axis caused by external vibrations is prevented. Further, a speckle pattern generated in propagating through an optical fiber is eliminated.

Abstract: The laser beam generating apparatus (light source apparatus) comprising a laser oscillator structured as a ring resonator is provided with a plurality of excitation light sources and a plurality of solid state laser active media excited by these excitation light sources respectively, and these solid state laser active media are disposed separately each other on the optical path in the ring resonator. A high power laser beam is obtained stably and efficiently.

Abstract: A laser beam generator includes first and second mirrors, a laser light source, a laser medium, a non-linear optical crystal element and a birefringent element. The laser light source generates a pumping light beam. The laser medium, arranged between the first and second mirrors, is irradiated with the pumping light beam via one of the mirrors to generate a fundamental laser beam based on the pumping light beam. The non-linear optical crystal element is arranged between the first and second mirrors to generate a second harmonic laser beam under the type II phase matching as the fundamental laser beam from the laser medium is passed through it in resonant oscillation. The birefringent element has its one surface at a pumping light beam inlet side coated with a high reflectance coating and has its opposite surface parallel to it with a nonreflective coating.

Abstract: The UV laser light outgoing from a UV laser light source 1 is modulated in intensity by a light modulator 2 in accordance with the subsidiary information so as to fall on a mirror 14 via lenses 3, 4, a phase diffraction lattice 5 and a half mirror 11. The UV laser light is then reflected by the mirror 14 and condensed by an objective lens 6 so as to be radiated on an optical disc 8. The UV laser light outgoing from the UV laser light source 1 falls on a phase diffraction lattice via a light modulator 2 and lenses 3 and 4 so as to be radiated on the optical disc 8 via the half mirror 11, mirror 14 and the objective lens 6. On the other hand, the reflected light of the visible laser light reflected by the optical disc 8 falls on the half mirror 11 via the objective lens 6 and the mirror 14 so as to be reflected by the half mirror 11 to fall on a photodetector 13 via a cylindrical lens 12.

Abstract: A light exposure illuminating apparatus is provided which, employing harmonics of a continuously outputted laser beam, is small-sized, inexpensive and free from speckles and which achieves a high light source utilization efficiency. Specifically, a harmonics generating 1 generates fourth harmonics which are reflected and swept via a scanning lens 2 by a polygonal mirror 3. A cylindrical reflecting mirror radiates the fourth harmonics reflected by the polygonal mirror 3 on an arcuate aperture formed in a light exposure mask by a sweeping movement. The light of fourth harmonics transmitted through the arcuate aperture reaches a reticle 7 set on a semiconductor pattern. The illuminating light passed through the reticle 7 is projected on a wafer 9 via a concave mirror 5 and a convex mirror 76. The area of light exposure may be increased since the reticle 7 and the wafer 9 are moved in synchronism with the scanning of the scanning optical system.

Abstract: The present invention provides an ultraviolet optical part having an ultraviolet optical thin film having a high durability against ultraviolet rays. The ultraviolet optical part is used in connection with ultraviolet rays continuously generated in a wavelength of 200 through 300 nm, and comprises an optical component and an ultraviolet optical thin film formed the optical component, wherein the ultraviolet optical thin film comprises a material having a thermal conductivity of 0.01 J.multidot.cm.sup.-1 .multidot.sec.sup.-1 .multidot.K.sup.-1 or greater. The ultraviolet optical thin film may comprise an HfO.sub.2 layer 10 and MgF.sub.2 layer 11, or may comprise an HfO.sub.2 layer 10, an MgO layer 12, and MgF.sub.2 layer 11. Further, the present invention provides a wavelength-changing device having a high durability against ultraviolet rays, the wavelength-changing device comprising a non-linear optical crystal and the ultraviolet optical thin film formed on the optical crystal.

Abstract: An optical pick-up apparatus includes a light source, an objective lens, a beam splitter, a detector, a first optical compensating device and a second optical compensating device. The objective lens converges a light beam emitted from the light source at one point on an optical axis. The beam splitter separates the light beam emitted from the light source from a returning light reflected on an optical disc. The detector detects the returning light separated from the light beam emitted from the light source. The first optical compensating device has a convex aspherical surface represented by X.alpha.R.sup.4 and is located on an optical path where the light beam is emitted from the light source. The second optical compensating device has a concave aspherical surface represented by +.alpha.R.sup.4 and is located on an optical path where the light beam is emitted from the light source.

Abstract: A lens evaluating device for measuring the optical transfer function of the lens under evaluation for evaluating the lens. The lens evaluating device includes an exposure light source, a converging lens for converging a light beam radiated from the exposure light source at a point, a characteristics evaluating pattern onto which the light beam outputted from the converging lens is converged by the lens under evaluation to form an image on it, a detection unit for receiving a return light beam having scanned the characteristics evaluating pattern via the lens under evaluation for detecting changes in reflection intensity of the return light beam, and an analysis unit for executing frequency analysis of the detected results from the detection unit for measuring the optical transfer function. The results of detection by the detection unit are subjected to a frequency analysis using a spectrum analyzer for measuring the optical transfer function of the lens under evaluation for evaluating the lens.

Abstract: A laser beam generator includes first and second mirrors, a laser light source, a laser medium, a non-linear optical crystal element and a birefringent element. The laser light source generates a pumping light beam. The laser medium, arranged between the first and second mirrors, is irradiated with the pumping light beam via one of the mirrors to generate a fundamental laser beam based on the pumping light beam. The non-linear optical crystal element is arranged between the first and second mirrors to generate a second harmonic laser beam under the type II phase matching as the fundamental laser beam from the laser medium is passed through it in resonant oscillation.