Abstract: To suppress the amplification of spontaneous emission light in a principal plane width direction to thereby suppress a gain in directions other than a beam axis direction and output a high-power laser, in a solid-state laser element of a plane waveguide type that causes a fundamental wave laser beam to oscillate in a beam axis direction in a laser medium of a flat shape and forms a waveguide structure in a thickness direction as a direction perpendicular to a principal plane of the flat shape in the laser medium, inclined sections 12 are provided on both sides of the laser medium, the inclined sections 12 inclining a predetermined angle to reflect spontaneous emission light in the laser medium to a principal plane side of the flat shape, the spontaneous emission light traveling in the beam axis direction and a principal plane width direction as a direction perpendicular to the thickness direction.

Abstract: A planar waveguide laser device forms a waveguide by a plate-like laser medium (1) having birefringence and clad (2a, 2b) attached to at least one of the surfaces of the laser medium (1) perpendicular to its thickness direction, amplifies laser light by a gain produced by excitation light incident on the laser medium (1), and performs laser oscillation. The laser medium (1) is formed of a material having an optic axis on a cross section perpendicular to the light axis, which is the laser travelling direction. The clad (2a, 2b) is formed of a material having a refractive index in a range between refractive indexes of two polarized lights that travel along the light axis in the laser medium (1) and have oscillation surfaces that are orthogonal to each other. The planar waveguide laser device readily oscillates linearly polarized laser light.

Abstract: A planar waveguide laser device forms a waveguide by a plate-like laser medium (1) having birefringence and clad (2a, 2b) attached to at least one of the surfaces of the laser medium (1) perpendicular to its thickness direction, amplifies laser light by a gain produced by excitation light incident on the laser medium (1), and performs laser oscillation. The laser medium (1) is formed of a material having an optic axis on a cross section perpendicular to the light axis, which is the laser travelling direction. The clad (2a, 2b) is formed of a material having a refractive index in a range between refractive indexes of two polarized lights that travel along the light axis in the laser medium (1) and have oscillation surfaces that are orthogonal to each other. The planar waveguide laser device readily oscillates linearly polarized laser light.

Abstract: A planar waveguide laser device forms a waveguide by a plate-like laser medium having birefringence and clad attached to at least one of the surfaces of the laser medium perpendicular to its thickness direction, amplifies laser light by a gain produced by excitation light incident on the laser medium, and performs laser oscillation. The laser medium is formed of a material having an optic axis on a cross section perpendicular to the light axis, which is the laser travelling direction. The clad is formed of a material having a refractive index in a range between refractive indexes of two polarized lights that travel along the light axis in the laser medium and have oscillation surfaces that are orthogonal to each other. The planar waveguide laser device readily oscillates linearly polarized laser light.

Abstract: A wavelength converting element that is of a planar waveguide type, includes a plate-like nonlinear optical material, and performs a wavelength conversion on a fundamental wave of a laser beam by propagating the fundamental wave in a plurality of laser oscillation modes in a direction perpendicular to a main surface of the plate-like nonlinear optical material, the direction being perpendicular to an optical axis, wherein periods of polarization inversions of the nonlinear optical material are changed so that each of the periods has a width of a phase matching band A that includes phase matching conditions of at least two of the plurality of laser oscillation modes and so that a non-polarization-inversion region and a polarization inversion region are formed in the nonlinear optical material.

Abstract: A wavelength conversion laser device includes a solid-state laser element having a waveguide structure including a laser medium that amplifies laser beams by providing a gain generated due to absorption of pump light to the laser beams and outputs a fundamental wave, and a wavelength conversion element having a waveguide structure including a nonlinear optical material that converts a part of a fundamental wave output from the solid-state laser element to a second harmonic, to resonate the fundamental wave by an optical resonator structure including the solid-state laser element and the wavelength conversion element and outputs a second harmonic from the wavelength conversion element.

Abstract: To achieve a solid-state laser element capable of outputting a high-power laser, in a planar waveguide type solid-state laser element that causes a plurality of fundamental laser beams to oscillate in a direction of an optic axis within a flat plate-like laser medium, and forms a waveguide structure in a thickness direction of the laser medium, which is a direction perpendicular to a principal surface of the flat plate-like laser medium, the laser medium is separated in a principal-surface width direction of the laser medium, which is a direction perpendicular to the direction of the optic axis and the thickness direction of the laser medium, by a groove extending in the direction of the optic axis within the laser medium.

Abstract: Not only abnormality of a light output to an exterior but also overturning, vibration, disassembly, deformation, or breakage of a display apparatus including a case and a screen are reliably and promptly detected. A projection display apparatus includes a light source (22) for generating illumination light, which is provided in a case (28) having a light-shielding function, a movable aperture (23) for adjusting the amount of illumination light from the light source (22), a light valve (9) for adjusting the amount of light based on an image signal to generate image light for forming an image from the illumination light, a projection optical system (10) for enlarging the image light from the light valve (9), and a transmission-type screen (29) for displaying the image, which is provided to a window of the case (28).

Abstract: To suppress the amplification of spontaneous emission light in a principal plane width direction to thereby suppress a gain in directions other than a beam axis direction and output a high-power laser, in a solid-state laser element of a plane waveguide type that causes a fundamental wave laser beam to oscillate in a beam axis direction in a laser medium of a flat shape and forms a waveguide structure in a thickness direction as a direction perpendicular to a principal plane of the flat shape in the laser medium, inclined sections 12 are provided on both sides of the laser medium, the inclined sections 12 inclining a predetermined angle to reflect spontaneous emission light in the laser medium to a principal plane side of the flat shape, the spontaneous emission light traveling in the beam axis direction and a principal plane width direction as a direction perpendicular to the thickness direction.

Abstract: A wavelength converting element that is of a planar waveguide type, includes a plate-like nonlinear optical material, and performs a wavelength conversion on a fundamental wave of a laser beam by propagating the fundamental wave in a plurality of laser oscillation modes in a direction perpendicular to a main surface of the plate-like nonlinear optical material, the direction being perpendicular to an optical axis, wherein periods of polarization inversions of the nonlinear optical material are changed so that each of the periods has a width of a phase matching band A that includes phase matching conditions of at least two of the plurality of laser oscillation modes and so that a non-polarization-inversion region and a polarization inversion region are formed in the nonlinear optical material.

Abstract: To achieve a solid-state laser element capable of outputting a high-power laser, in a planar waveguide type solid-state laser element that causes a plurality of fundamental laser beams to oscillate in a direction of an optic axis within a flat plate-like laser medium, and forms a waveguide structure in a thickness direction of the laser medium, which is a direction perpendicular to a principal surface of the flat plate-like laser medium, the laser medium is separated in a principal-surface width direction of the laser medium, which is a direction perpendicular to the direction of the optic axis and the thickness direction of the laser medium, by a groove extending in the direction of the optic axis within the laser medium.

Abstract: Provided is a device capable of oscillating a plurality of oscillation modes within a laser medium for obtaining a fundamental wave output which is easy in output scaling and high in luminance, thereby enabling a second harmonic conversion which is high in efficiency. The device includes: a laser medium (5) that is planar, has a waveguide structure in a thickness direction of a cross-section that is perpendicular to an optical axis (6), and has a cyclic lens effect in a direction perpendicular to the optical axis (6) and the thickness direction; a clad (4) that is bonded onto one surface of the laser medium (5); and heat sink (3) that is bonded onto one surface side of the laser medium (5) through the clad (4), and in the device, a laser oscillation includes a laser oscillation that oscillates in a waveguide mode of the laser medium (5), and a laser oscillation that oscillates in a plurality of resonator modes that are generated by a cyclic lens effect of the laser medium (5).

Abstract: A wavelength converting laser device includes a laser diode producing laser light and including an optical resonator having a pair of facing reflectors, including a reflecting surface having a shape reducing loss in the optical resonator, with regard to a specific horizontal transverse mode of laser light as compared to the loss in the optical resonator for other horizontal transverse modes, and a wavelength converter for converting the laser light into harmonic light.

Abstract: A wavelength conversion laser device includes a solid-state laser element having a waveguide structure including a laser medium that amplifies laser beams by providing a gain generated due to absorption of pump light to the laser beams and outputs a fundamental wave, and a wavelength conversion element having a waveguide structure including a nonlinear optical material that converts a part of a fundamental wave output from the solid-state laser element to a second harmonic, to resonate the fundamental wave by an optical resonator structure including the solid-state laser element and the wavelength conversion element and outputs a second harmonic from the wavelength conversion element.

Abstract: A planar waveguide laser device forms a waveguide by a plate-like laser medium having birefringence and clad attached to at least one of the surfaces of the laser medium perpendicular to its thickness direction, amplifies laser light by a gain produced by excitation light incident on the laser medium, and performs laser oscillation. The laser medium is formed of a material having an optic axis on a cross section perpendicular to the light axis, which is the laser travelling direction. The clad is formed of a material having a refractive index in a range between refractive indexes of two polarized lights that travel along the light axis in the laser medium and have oscillation surfaces that are orthogonal to each other. The planar waveguide laser device readily oscillates linearly polarized laser light.

Abstract: Provided are a speckle removing light source capable of removing speckle by using laser light whose wavelength is temporally changed and a lighting apparatus for producing an image from which the speckle is removed. Included are a light source for outputting laser light, and a light frequency modulator for temporally changing a wavelength of the laser light. The light frequency modulator has a predetermined period set for changing the wavelength of the laser light. Also, provided is a lighting apparatus, including a spatial light modulator illuminated with the laser light outputted from the speckle removing light source to produce an image. The spatial light modulator has a period set for producing the image, which is longer than the period for changing the wavelength of the laser light by the light frequency modulator.

Abstract: A reflection element 3 disposed in an optical waveguide element 2 returns a part of light to a semiconductor laser diode element 1 so that the semiconductor laser diode element 1 oscillates in a coherent collapse mode, and a semiconductor light amplifier 7 is optically coupled to the optical waveguide element 2, and amplifies an optical output from optical waveguide element 2, so as to provide a high-power fundamental-wave light source.

Abstract: Provided is a lighting apparatus capable of uniformly and efficiently lighting a spatial light modulator. The lighting apparatus includes: a light source for outputting laser light; a multimode optical fiber in which the laser light outputted from the light source propagates through an internal core whose lateral cross section is a substantially polygonal outer diameter shape; and spatial light modulator for producing an image with illumination light from the multimode optical fiber. In the lighting apparatus, the laser light is outputted from the light source and is propagated to the multimode optical fiber in which an outer diameter shape of the lateral cross section of the core is a substantially polygonal shape, whereby the spatial light modulator can be uniformly and efficiently lighted.

Abstract: An allowable temperature range satisfying phase matching conditions of a wavelength conversion device is widened. A wavelength conversion light source includes a semiconductor laser diode device (1) applied with an antireflection film (3), a lens (4) arranged opposite to the semiconductor laser diode device (1), an optical fiber (5) having a Bragg grating (6) arranged in a core thereof, and a wavelength conversion device (8) formed of a nonlinear optical crystal on which light from the semiconductor laser diode device (1) is incident. In the wavelength conversion light source, the semiconductor laser diode device (1) oscillates in coherent collapse mode.

Abstract: A wavelength converting laser device includes a laser diode producing laser light and including an optical resonator having a pair of facing reflectors, including a reflecting surface having a shape reducing loss in the optical resonator, with regard to a specific horizontal transverse mode of laser light as compared to the loss in the optical resonator for other horizontal transverse modes, and a wavelength converter for converting the laser light into harmonic light.