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: 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.

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: 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. Provided is a speckle removing light source, including: a light source for outputting laser light; and a light frequency modulator for changing a wavelength of the laser light, in which: the wavelength of the laser light outputted from the light source is temporally changed by the light frequency modulator; and 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, in which the spatial light modulator has a period set for producing the image, and the period is longer than the period for changing the wavelength of the laser light by the light frequency modulator.

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: 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: 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: An optical signal emitted from a semiconductor laser is converged by a lens and then received by a single uniaxial birefringent crystal having a C axis that is inclined at an angle other than 90 degrees against a laser optical axis to output an optical signal having a polarized wave component of constant intensity corresponding to the wavelength of the optical signal regardless of temperature changes. The optical signal has an ordinary ray vibrating in a direction perpendicular to a plane including both the C axis and the laser optical axis, and an extraordinary ray vibrating in a direction perpendicular to both the ordinary ray and the laser optical axis. A first main photo detector detects the intensity of a p-polarized component of the optical signal that has passed through a polarizer and a second photo detector directly receives the optical signal converged by the lens.

Abstract: A wavelength filter includes a solid material that is optically transparent and including a pair of planar surfaces substantially parallel to each other; and a supporting member that supports the solid material on a planar surface of the solid material other than the pair of planar surfaces, the supporting member having a rigidity higher than that of the solid material. The solid material is a birefringent material of which an optical axis makes a predetermined angle with respect to a normal to the pair of planar surfaces, and the wavelength filter selects light having a wavelength that is determined by an optical length between the pair of planar surfaces by resonating the light between the pair of planar surfaces.

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: On a plate of birefringent crystal made of an LiNbO3 crystal or an LiTaO3 crystal, a conductive substance is adhered to the whole periphery of side surfaces of the plate that intersect an incident surface of a laser beam, thereby to form a wave plate. A polarizer is provided at the latter stage of the wave plate. A wavelength is monitored based on an output from the polarizer. With this arrangement, based on the use of the LiNbO3 crystal or the LiTaO3 crystal that can be manufactured by a large quantity at low cost, it is possible to obtain polarization characteristics and wavelength discrimination characteristics that are stable against environmental changes such as temperature and external stress, by suppressing the pyroelectric effect and the piezoelectric effect of these materials.

Abstract: A solid-state laser device includes: a first solid-state laser medium 1 that emits light at a first wavelength that produces fluorescence through excitation; a second solid-state laser medium 2 that is arranged coaxially, is excited by the light at the first wavelength emitted by the first solid-state laser medium 1, and emits light at a second wavelength; two reflection means 3 and 4, which are arranged coaxially with the solid-state laser media and on both outsides of the solid-state laser media, for resonating a light component generated in an axis direction among the fluorescence; and an excitation light source 5 that excites one of the solid-state laser media, wherein the reflection means 4 has a predetermined reflectance with respect to each of the two wavelengths and laser light at the two different kinds of wavelengths is outputted separately or simultaneously with one resonator and one excitation light source.

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 filter includes a solid material that is optically transparent and including a pair of planar surfaces substantially parallel to each other; and a supporting member that supports the solid material on a planar surface of the solid material other than the pair of planar surfaces, the supporting member having a rigidity higher than that of the solid material. The solid material is a birefringent material of which an optical axis makes a predetermined angle with respect to a normal to the pair of planar surfaces, and the wavelength filter selects light having a wavelength that is determined by an optical length between the pair of planar surfaces by resonating the light between the pair of planar surfaces.

Abstract: An oscillation state of a semiconductor laser is decided. Injection current to the first and second light reflectors of the semiconductor laser are simultaneously swept based on the oscillation state of the semiconductor laser to obtain current conditions of the injection current to the first and second light reflectors that carry out single-mode oscillation in a target wavelength. The semiconductor laser is drive controlled with the obtained current conditions.