Abstract: A light beam scanning display for displaying an image on a drawing screen by modulating laser beams from three primary color light sources, the three primary color light sources being arranged in close vicinity to each other, based on image data respectively and then scanning the laser beams, the light beam scanning display comprising: a parallelizing section that parallelizes respective laser beams; wherein the laser beams being parallelized by the parallelizing section to form one pixel of a drawn image on the drawing screen via different optical paths such that optical axes of the laser beams do not overlap with each other.

Abstract: In a laser module in which laser beams emitted from semiconductor laser elements are collimated by collimator lenses, and condensed by an optical condensing system so that the laser beams converge at a light-entrance end face of an optical fiber. The semiconductor laser elements and the collimator lenses are contained in a hermetically sealed, first package which includes a front wall having a window arranged for passage of the laser beams, and a portion of the optical condensing system and the light-entrance end face are contained in a hermetically sealed, second package which is fixed to the front wall. The cross section of the second package perpendicular to the optical axis of the optical fiber at the light-entrance end face is smaller than the cross section of the first package parallel to the cross section of the second package.

Abstract: A laser module includes: one or more semiconductor laser elements which emit one or more divergent laser beams; one or more collimator lenses which collimate the one or more divergent laser beams; a condensing lens which condenses the one or more collimated laser beams, and make the one or more collimated laser beams converge at a convergence position; an optical fiber which is arranged in such a manner that the convergence position is located on the light-entrance end face; and a package which contains the one or more semiconductor laser elements and the one or more collimator lenses, does not contain the condensing lens and the light-entrance end face, and is hermetically sealed.

Abstract: A wavelength selecting optical element such as a narrow band-pass filter or the like is provided between a semiconductor laser and a light wavelength conversion element formed of a bulk-shaped wavelength conversion crystal. The wavelength selecting optical element selects a wavelength of a laser beam which is to be reflected by an end surface of the light wavelength conversion element to be fed back to the semiconductor laser.

Abstract: A display device is made up of a transparent porous layer, a colored layer, and a penetrant-moving part. The transparent porous layer is formed from a transparent material and has pores into which a penetrant is penetrable. The colored layer is stacked on one surface of the transparent porous layer. The penetrant-moving part is used for performing penetration of the penetrant into the transparent porous layer or discharge of the penetrant from the transparent porous layer. After the penetration of the penetrant into the transparent porous layer performed by the penetrant-moving part, the transparent porous layer becomes transparent and therefore the colored layer is displayed through the transparent porous layer. After the discharge of the penetrant from the transparent porous layer performed by the penetrant-moving part, the transparent porous layer becomes opaque and therefore the transparent porous layer is displayed.

Abstract: A display device includes a porous body impregnated with electroendosmosis liquid, a transparent plate which is opposed to the porous body with a space intervening therebetween and is provided on its side facing the porous body with a light diffusive reflection surface and on the other side opposite to the one side with a light transmission surface, and an electric field forming system which forms an electric field acting on the electroendosmosis liquid and controls whether the electroendosmosis liquid is brought into contact with the light diffusive reflection surface by changing the electric field to selectively move the electroendosmosis liquid toward the porous body or the space.

Abstract: A light wavelength converting module is provided in which generation of noise due to return light is prevented and a wave whose wavelength is converted can be obtained stably. The light wavelength converting module is formed by a semiconductor laser from which a fundamental wave exits, and a light wavelength converting element which is optically coupled to the semiconductor laser and which converts a wavelength of the fundamental wave which enters from the semiconductor laser. A wavelength plate is disposed at a light exiting side of the light wavelength converting element. An IR cutting filter, which serves as a removing means for removing the fundamental wave from a second harmonic, is disposed between the wavelength plate and the light wavelength converting element.

Abstract: A light wavelength converting element which can reduce an amount of light fed-back to a semiconductor laser. The light wavelength converting element converts a wavelength of a fundamental wave which enters from a first end surface side of an optical waveguide to thereby emit a converted wavelength wave from a second end surface side thereof. The second end surface is inclined with respect to the side surface of the optical waveguide. Also provided is a wavelength stabilized laser having a semiconductor laser, a device which feeds a laser beam emitted from the semiconductor laser back to the semiconductor laser, and a band-pass filter. An optical length between the semiconductor laser and the device is made to be longer than a coherent length of the semiconductor laser, thus improving linearity of a current vs. light output characteristic.

Abstract: A semiconductor laser device includes a semiconductor laser element having a pair of cleavage planes which allows laser oscillation therebetween in a plurality of Fabry-Perot modes, an external resonator being coupled to the semiconductor laser element and including a wavelength selection element which has a passband including more than one wavelength of more than one Fabry-Perot mode out of the plurality of Fabry-Perot modes, and a high-frequency superimposing unit which superimposes a high-frequency current on a driving current of the semiconductor laser element.

Abstract: A light wavelength converting module is provided in which generation of noise due to return light is prevented and a wave whose wavelength is converted can be obtained stably. The light wavelength converting module is formed by a semiconductor laser from which a fundamental wave exits, and a light wavelength converting element which is optically coupled to the semiconductor laser and which converts a wavelength of the fundamental wave which enters from the semiconductor laser. A wavelength plate is disposed at a light exiting side of the light wavelength converting element. An IR cutting filter, which serves as a removing means for removing the fundamental wave from a second harmonic, is disposed between the wavelength plate and the light wavelength converting element.

Abstract: A laser diode pumped solid state laser includes a solid laser medium, and an index optical waveguide type laser diode which emits a pumping light beam for pumping the laser medium. A high-frequency which is higher than a response frequency of the solid laser medium and is of an amplitude which makes a percentage modulation of the light output of the laser diode a value not smaller than 50% and smaller than 100% is superposed on a drive current for the laser diode.

Abstract: In a laser light source comprised of a semiconductor light-emitting element and a waveguide-type wavelength selection element, the semiconductor light-emitting element emits light, and the waveguide-type wavelength selection element selects a wavelength of the light emitted from the semiconductor light-emitting element. A first end face of the semiconductor light-emitting element and an end face of the waveguide-type wavelength selection element are butt-coupled. An antireflection optical system for the wavelength selected by the waveguide-type wavelength selection element is formed between the first end face of the semiconductor light-emitting element and the end face of the waveguide-type wavelength selection element. A second end face of the semiconductor light-emitting element and the waveguide-type wavelength selection element form an external resonator in which light having the wavelength selected by the waveguide-type wavelength selection element resonates.

Abstract: An electro-optical waveguide element with reduced DC drift phenomena is presented. The waveguide element is made up of an optical waveguide formed on a substrate possessing electro-optical effects, at least a pair of electrodes closely attached to the optical waveguide with a buffer layer sandwiched between the substrate and the electrodes, and a driver circuit for applying a voltage between the electrodes. The buffer layer is made of a material having a dielectric constant in the range of 20-1000. The buffer layer is more preferably made of a material having a dielectric constant in the range of 20-200. The material of the buffer layer is selected from the group consisting of HfO.sub.2, TiO.sub.2, SrTiO.sub.3, BaTiO.sub.3, LiNbO.sub.3, LiTaO.sub.3, Pb(Zr, Ti)O.sub.3, and (Pb, La)(Zr, Ti)O.sub.3.

Abstract: An optical wavelength conversion element includes an optical waveguide which is formed on a ferroelectric crystal substrate having a nonlinear optical effect and extends along one surface of the substrate, and domain reversals which are periodically formed in the optical waveguide and arranged in a direction. The orientation of the spontaneous polarization of the substrate is reversed in the domain reversals and the optical wavelength conversion element converts the wavelength of a fundamental wave travelling in the direction in which the domain reversals are arranged under the guidance of the optical waveguide. The orientation of the spontaneous polarization of the substrate is at an angle .theta. larger than 0.degree. and smaller than 90.degree. to the surface of the substrate in a plane normal to the direction in which the fundamental wave is guided.

Abstract: A waveguide type electro-optical element is made up of a proton-exchanged optical waveguide formed on a substrate which possesses an electro-optical effect. At least one pair of electrodes is formed on the substrate adjacent to the optical waveguide with a buffer layer being disposed between the substrate and the electrodes. A guide beam propagating through the waveguide is diffracted as a result of the application of a voltage to the electrodes. The buffer layer is made of material which has a specific resistance ranging between 10.sup.7 -10.sup.11 .OMEGA.cm. The optical waveguide may be of a form having a split-type optical waveguide consisting of the combination of two Y-shaped waveguides, and a pair of channel optical waveguides constituting a directional coupler.