Abstract: A semiconductor laser device with external resonator with stable longitudinal mode regardless of variation of drive current is disclosed. The device includes: a semiconductor light-emitting element having a pair of end faces with a light emitting section disposed therebetween, and an external resonator configured to oscillate light emitted from the semiconductor light-emitting element, the external resonator being formed by a resonator mirror disposed outside the semiconductor light-emitting element and one of the pair of end faces that is farther from the resonator mirror, wherein, as the semiconductor light-emitting element, a semiconductor light-emitting element having a structure which does not oscillate light emitted therefrom by itself is used.

Abstract: A semiconductor laser device with external resonator with stable longitudinal mode regardless of variation of drive current is disclosed. The device includes: a semiconductor light-emitting element having a pair of end faces with a light emitting section disposed therebetween, and an external resonator configured to oscillate light emitted from the semiconductor light-emitting element, the external resonator being formed by a resonator mirror disposed outside the semiconductor light-emitting element and one of the pair of end faces that is farther from the resonator mirror, wherein, as the semiconductor light-emitting element, a semiconductor light-emitting element having a structure which does not oscillate light emitted therefrom by itself is used.

Abstract: A single longitudinal mode diode laser module including a laser diode (1) and an external resonator using a volume holographic grating (3) having a prescribed reflective bandwidth is made amenable to automatic power control by controlling the temperature of the laser diode such that the laser power may be allowed to increase monotonically with an increase in the input current. Therefore, the output laser power can be controlled at a constant level by automatic power control or by adjusting the input current while monitoring the laser power at any desired level of the laser power.

Abstract: A diode laser module includes a laser diode (1), an anamorphic prism pair (5) consisting of a pair of prisms (3, 4) having mutually different apex angles and/or made of material having mutually different refractive indices, and a partial reflective mirror (6; 16) disposed on a side of the anamorphic prism pair away from the laser diode and having a planar or spherical surface facing the anamorphic prism pair and coated with partial reflective coating (6a; 16a). The wavelength of the laser output can be changed by adjusting the position of the partial reflective mirror.

Abstract: A light deflector for deflecting a propagation direction of laser includes: a first metallic piece and a second metallic piece spaced apart from each other; and a transparent medium and an electronic cooling element disposed between the first metallic piece and the second metallic piece such that each of the transparent medium and the electronic cooling element is in contact with the first metallic piece and the second metallic piece. The electronic cooling element creates a temperature difference between the first metallic piece and the second metallic piece to vary a refractive index of the transparent medium.

Abstract: A laser welding apparatus includes a laser welding unit including a first lens adapted to focus a laser beam; a second lens adapted to diffuse the laser beam to the first lens; and a third lens adapted to guide the laser beam to the second lens. The relative positions of the first lens, the second lens, and the third lens, are adjusted to adjust a diffusion angle and a beam width of the laser beam entering the first lens. The laser welding apparatus performs: actuating the laser welding unit to travel at a predetermined speed along a predetermined trajectory; directing the laser beam at a first welding spot; adjusting the focal length to focus the laser beam at the first welding spot; holding the laser focal spot size substantially constant; and directing the laser beam at a second welding spot after completion of welding for the first welding spot.

Abstract: A laser optical system using optical fiber transmission, includes a first optical fiber for transmitting laser light emitted from a laser oscillator, a collimator lens for collimating laser light emitted from the first optical fiber, a spherical array lens including a plurality of cells for converging laser light emitted from the collimator lens into a plurality of spots, a plurality of second optical fibers each having a smaller core diameter than the first optical fiber and configured to admit the laser light converged into the corresponding spot by the spherical array lens, the second optical fibers having output ends that have mutually parallel axial lines and are arranged linearly in a single row, and a linearization optical unit for shaping laser light emitted from the second optical fibers into laser light having a linear cross section at an illuminated surface.

Abstract: A laser optical system using optical fiber transmission, includes a first optical fiber for transmitting laser light emitted from a laser oscillator, a collimator lens for collimating laser light emitted from the first optical fiber, a spherical array lens including a plurality of cells for converging laser light emitted from the collimator lens into a plurality of spots, a plurality of second optical fibers each having a smaller core diameter than the first optical fiber and configured to admit the laser light converged into the corresponding spot by the spherical array lens, the second optical fibers having output ends that have mutually parallel axial lines and are arranged linearly in a single row, and a linearization optical unit for shaping laser light emitted from the second optical fibers into laser light having a linear cross section at an illuminated surface.

Abstract: In a UV laser system, the problem of deposition of residues of organic substances on the surfaces of optical components is avoided so that the reduction in the laser output can be avoided. A wavelength converting crystal (10) used for the generation of a UV laser light is provided with a reflective plane (14) that selectively reflects the UV laser light (23) to cause the UV laser light to emit from a part of the wavelength converting crystal different from an optical path of a basic wavelength laser light (21). The residues may be deposited on the part of the wavelength converting crystal from which the UV laser light is emitted, but not in the part of thereof through which the basic wavelength laser light passes so that the generation process for the UV laser light is not affected by the deposition of the residues.

Abstract: An infrared detector comprises: first and second container members bonded to each other along an annular bonding portion to define a vacuum-sealed inner space, where the second container member has an infrared-transmissive property; an infrared detecting element disposed in the inner space; a first annular metallization layer formed on the bonding portion of the first container member; a second annular metallization layer formed on the bonding portion of the second container member; a solder metal for air-tightly bonding the first metallization layer and the second metallization layer; and a third metallization layer formed in a vicinity of one of the first and second metallization layers such that the third metallization layer overlaps the other of the first and second metallization layers at least partly.

Abstract: In an infrared detector package, a first annular metallized layer (6a, 6b) is formed along the annular shoulder (4a) of a casing member (4), and a second annular metallized layer (7) is formed along the annular mating surface of a window member (5). Brazing material (8) is integrally interposed between the first and second metallized layers. At least one of the first and second annular metallized layers comprises a mutually separated concentric portions (6a, 6b), and the brazing material extends across the two mutually separated concentric portions. During the manufacturing process, brazing material is deposited on one of the two mutually separated concentric portions, and is allowed to flow along the opposing metallized surface until the brazing material reaches the other of the two mutually separated concentric portions.

Abstract: Provided is a diode-pumped solid-state laser adapted for an intracavity sum-frequency mixing for generating a laser radiation of a visible wavelength range by performing a sum-frequency mixing of two laser inputs in a laser resonant cavity. A pair of laser resonators of two different wavelengths are formed along a common optical path and an intracavity sum-frequency mixing is conducted so as to obtain a laser radiation at a sum-frequency wavelength by placing a nonlinear optical crystal on this common optical path. By suitably selecting the properties of the reflective surfaces that form the laser resonators, a laser radiation of a relatively short wavelength range can be obtained even though the wavelength of the pumping laser beam is relatively long, and an extremely high conversion efficiency can be achieved.

Abstract: A horizontally elongated laser beam is divided into a plurality of beam sections which are arranged along the horizontal direction and vertically deflected to different degrees by a beam deflecting beam guide, and the beam sections leaving the beam deflecting beam guide at different vertical positions are horizontally deflected by a beam converging beam guide to different degrees so that the beam sections may converge along a vertical line, and the laser beam which was initially laterally elongated may be shaped into a more circular cross section which is desirable for pumping a laser system and other applications. Each of the beam guides may consist of a plurality of transparent plate members which are placed one over the other, and each beam segment is conduct through a corresponding one of the plate member along a path parallel to the major surface of the plate members.