Abstract: A laser device is provided including a surface emitting laser array configured to emit light, an optical system disposed in an optical path of light that is emitted from the surface emitting laser, a laser resonator which the light passed through the optical system enters, where the optical system includes a first optical element configured to collimate the light emitted from the surface emitting laser, and a second optical element configured to collect and condense the light collimated by the first optical element.

Abstract: An optical window member includes an incident surface onto which a laser light is directed and an exit surface from which the laser light exits. At least one of the incident surface and the exit surface has a plurality of protrusions or recesses formed therein. An interval between centers of adjacent protrusions or adjacent recesses is shorter than or equal to a wavelength of the laser light.

Abstract: A laser device is provided including a surface emitting laser array configured to emit light, an optical system disposed in an optical path of light that is emitted from the surface emitting laser, a laser resonator which the light passed through the optical system enters, where the optical system includes a first optical element configured to collimate the light emitted from the surface emitting laser, and a second optical element configured to collect and condense the light collimated by the first optical element.

Abstract: A laser device is provided including a light source configured to emit light, a light transmission member configured to transmit the light emitted from the light source, a plurality of optical elements disposed in an optical path of the light transmitted by the light transmission member, a laser resonator which the light passed through the plurality of optical elements enter, and an adjuster configured to adjust a position of at least one of the plurality of optical elements.

Abstract: A laser device is provided including a light source configured to emit light, a laser resonator which the light emitted from the light source enters, a first optical element configured to increase a divergence angle of the light emitted from the laser resonator, a second optical element configured to collimate the light whose divergence angle is increased by the first optical element, and a third optical element configured to collect and condense the light collimated by the second optical element.

Abstract: A laser-diode pumped solid-state laser apparatus comprises at least one laser diode producing a pumping laser light, and at least one laser light generator including a monocrystalline substance doped with a dopant element and pumped with the pumping laser light from at least one laser diode, the monocrystalline substance containing the dopant element with a concentration profile such that the dopant element increases a concentration thereof in a direction perpendicular to a laser oscillation direction gently in the form of a slope from a near zero concentration.

Abstract: A diffraction grating with periodically arranged protrusions and grooves at a relatively narrow pitch and improved diffraction efficiency is disclosed. The protrusions of the grating are made of a material whose index of refraction is greater than that of the grooves, and the ratio of the width D of the protrusion to the pitch ? of the protrusion is set equal to or less than 0.4 (D/??0.4).

Abstract: A laser-diode pumped solid-state laser apparatus comprises at least one laser diode producing a pumping laser light, and at least one laser light generator including a monocrystalline substance doped with a dopant element and pumped with the pumping laser light from at least one laser diode, the monocrystalline substance containing the dopant element with a concentration profile such that the dopant element increases a concentration thereof in a direction perpendicular to a laser oscillation direction gently in the form of a slope from a near zero concentration.

Abstract: A polarization split device that includes an optically isotropic substrate, an optically anisotropic film, and a diffraction grating. The optically anisotropic film is formed on the optically isotropic substrate. The diffraction grating includes first and second cyclically structural portions. The first cyclically structural portion is formed on a front surface of the optically anisotropic film such that a depression in a rectangular shape is cyclically arranged with a predetermined pitch. The second cyclically structural portion includes an optically transparent material having a refractive index approximately equivalent to a refractive index of the optically anisotropic film and is configured to cover the first cyclically structural portion. Diffraction light having a diffraction angle greater than a predetermined angle among diffraction light diffracted by the diffraction grating is inhibited from being discharged outside.

Abstract: A polarization diffraction grating includes two media having different orientation states arranged alternately and cyclically, wherein each boundary between the media forms an oblique rectangular shape.

Abstract: A diffraction grating with periodically arranged protrusions and grooves at a relatively narrow pitch and improved diffraction efficiency is disclosed. The protrusions of the grating are made of a material whose index of refraction is greater than that of the grooves, and the ratio of the width D of the protrusion to the pitch ? of the protrusion is set equal to or less than 0.4 (D/??0.4).

Abstract: A diffraction grating with periodically arranged protrusions and grooves at a relatively narrow pitch and improved diffraction efficiency is disclosed. The protrusions of the grating are made of a material whose index of refraction is greater than that of the grooves, and the ratio of the width D of the protrusion to the pitch ? of the protrusion is set equal to or less than 0.4 (D/??0.4).

Abstract: A semiconductor laser pumped solid laser device is disclosed which enables a reduced size and high light output easily. The semiconductor laser pumped solid laser device has a plate-like laser material, and a semiconductor laser that emits a laser beam to pump the plate-like laser material to induce laser oscillation. Two end surfaces of the plate-like laser material act as two resonance surfaces of a resonator, and pumping light is introduced into the resonator through other side surface of the resonator than the resonance surfaces; the plate-like laser material includes plural regions each having different absorption coefficients and possesses finite absorption coefficients for the pumping light of different wavelengths, and absorption of the pumping light by the plate-like laser material is a maximum near a center of the plate-like laser material along an incident direction of the pumping light.

Abstract: A diffraction grating with periodically arranged protrusions and grooves at a relatively narrow pitch and improved diffraction efficiency is disclosed. The protrusions of the grating are made of a material whose index of refraction is greater than that of the grooves, and the ratio of the width D of the protrusion to the pitch ? of the protrusion is set equal to or less than 0.4 (D/??0.4).

Abstract: A solid-state laser apparatus includes a solid-state laser medium producing an output laser beam, the solid-state laser medium forming a microchip laser and having opposing end surfaces forming a laser cavity, a semiconductor laser array pumping the solid-state laser medium by a pumping laser beam, the semiconductor laser array injecting the pumping laser beam to the solid-state laser medium from a direction perpendicular to a direction of the output laser beam, the solid-state laser medium and the semiconductor laser array are mounted on a common mounting substrate.

Abstract: A diffractive optical element improves wavefront aberration for transmitted light. The diffractive optical element includes first and second substrates, an adhesive layer, a film, and an overcoat layer, all of which are formed of optically transparent materials. The film is glued on the first substrate via the adhesive layer. The film has a surface where a desired diffraction grating is formed in accordance with an irregularity thereof. The overcoat layer is formed on the film surface so as to fill a concave part of the diffractive grating. The second substrate is glued on the overcoat layer so as to make plane a surface of the overcoat layer. The adhesive layer and the film have an approximately equal refractive index.

Abstract: A diffraction grating with periodically arranged protrusions and grooves at a relatively narrow pitch and improved diffraction efficiency is disclosed. The protrusions of the grating are made of a material whose index of refraction is greater than that of the grooves, and the ratio of the width D of the protrusion to the pitch &Lgr; of the protrusion is set equal to or less than 0.4 (D/&Lgr;≦0.4).

Abstract: A polarization diffraction grating includes two media having different orientation states arranged alternately and cyclically, wherein each boundary between the media forms an oblique rectangular shape.

Abstract: A polarization split device includes an optically isotropic substrate, an optically anisotropic film, and a diffraction grating. The optically anisotropic film is formed on the optically isotropic substrate. The diffraction grating includes first and second cyclically structural portions. The first cyclically structural portion is formed on a front surface of the optically anisotropic film such that a depression is cyclically arranged with a predetermined pitch. The second cyclically structural portion includes an optically transparent material having a refractive index approximately equivalent to a refractive index of the optically anisotropic film and configured to cover the first cyclically structural portion. Diffraction light having a diffraction angle greater than a predetermined angle among diffraction light diffracted by the diffraction grating is inhibited from being discharged outside the optically isotropic substrate.

Abstract: A solid-state laser apparatus and method in which a laser crystal and a non-linear optical crystal are connected and unitarily combined by a spacer. An optical resonator is constructed between both ends thereof. An optical cavity where the laser light passes through is formed between the laser crystal and the non-linear optical crystal. An end surface of the laser crystal is treated by optical polishing to form a laser resonator in the optical cavity. Alignment between the crystal becomes unnecessary, and subsequent assembling is thus simplified. Fresnel reflection occurs on the end surface of a laser crystal treated only by the optical polishing due to an index of refraction coefficient difference.