Abstract: A laser light source device may include a laser diode, first and second optical elements, a diffraction grating, and a detector. The first optical element may collimate laser light emitted from the laser diode. The diffraction grating may reflect zero-order light in the collimated laser light in a predetermined direction other than a direction toward the laser diode and may reflect first-order light in the collimated laser light toward the laser diode. The second optical element may reflect the zero-order light reflected by the diffraction grating in a predetermined direction while transmitting a part of the zero-order light reflected by the diffraction grating. The detector may detect at least one of a wavelength and an intensity of the light that passes through the second optical element.

Abstract: An apparatus for producing a duplicate hologram recording medium includes: a positioning section configured to place the duplication master and the duplicate hologram recording medium at predetermined relative positions; an angle selective plate arranged between the duplication master and the duplicate hologram recording medium, the angle selective plate having an angle selective film whose transmittance changes in accordance with an incidence angle of a light beam; and a duplicating-reference-beam generating and radiating section generating a duplicating reference beam, and radiating the duplicating reference beam at such an incidence angle that the duplicating reference beam is transmitted through a predetermined region of a recording layer of the duplication master and is reflected by the angle selective film.

Abstract: A laser system includes a laser diode that oscillates in a multi-mode and has characteristics in which its oscillation wavelength varies with temperature, a grating that receives a light beam emitted from the laser diode and returns a diffracted beam to the laser diode, a mechanism that changes the wavelength of the diffracted beam returned to the laser diode, a wavelength detector that detects the wavelength of an output beam which is the same as that of the diffracted beam returned to the laser diode, a temperature regulator that maintains the laser diode at a predetermined temperature, and a control unit that controls the mechanism so that the output beam having a predetermined wavelength is output and controls the temperature regulator so that the laser diode oscillates at the predetermined wavelength.

Abstract: A laser apparatus is disclosed. An optical element receives at least a part of laser light emitted from a laser generation source and generates interference fringes. Each of first and second two-divided detectors has two detectors arranged in the direction of which the interference fringes appear. Each of the detectors detects an amount of light of the interference fringes. These two-divided detectors are spaced apart for an odd-number multiple of nearly ¼ period of interference fringes and disposed on a plane perpendicular to an optical path of the interference fringes. Each of first and second calculation sections calculates a first difference signal of detection signals of two detectors of the two-divided detector. A selection section selects one of the first and second difference signals. A determination section determines a wavelength of the laser light corresponding to a value of the difference signal selected from the first and second difference signals.

Abstract: A laser system includes a laser diode that oscillates in a multi-mode and has characteristics in which its oscillation wavelength varies with temperature, a grating that receives a light beam emitted from the laser diode and returns a diffracted beam to the laser diode, a mechanism that changes the wavelength of the diffracted beam returned to the laser diode, a wavelength detector that detects the wavelength of an output beam which is the same as that of the diffracted beam returned to the laser diode, a temperature regulator that maintains the laser diode at a predetermined temperature, and a control unit that controls the mechanism so that the output beam having a predetermined wavelength is output and controls the temperature regulator so that the laser diode oscillates at the predetermined wavelength.

Abstract: An apparatus for producing a duplicate hologram recording medium includes: a positioning section configured to place the duplication master and the duplicate hologram recording medium at predetermined relative positions; an angle selective plate arranged between the duplication master and the duplicate hologram recording medium, the angle selective plate having an angle selective film whose transmittance changes in accordance with an incidence angle of a light beam; and a duplicating-reference-beam generating and radiating section generating a duplicating reference beam, and radiating the duplicating reference beam at such an incidence angle that the duplicating reference beam is transmitted through a predetermined region of a recording layer of the duplication master and is reflected by the angle selective film.

Abstract: A laser apparatus is disclosed. An optical element receives at least a part of laser light emitted from a laser generation source and generates interference fringes. Each of first and second two-divided detectors has two detectors arranged in the direction of which the interference fringes appear. Each of the detectors detects an amount of light of the interference fringes. These two-divided detectors are spaced apart for an odd-number multiple of nearly ¼ period of interference fringes and disposed on a plane perpendicular to an optical path of the interference fringes. Each of first and second calculation sections calculates a first difference signal of detection signals of two detectors of the two-divided detector. A selection section selects one of the first and second difference signals. A determination section determines a wavelength of the laser light corresponding to a value of the difference signal selected from the first and second difference signals.

Abstract: A laser light source device includes a laser diode that emits multimode laser light, a first optical element that collimates the laser light emitted from the laser diode, a diffraction grating that reflects zero-order light in the collimated laser light in a predetermined direction other than a direction toward the laser diode and reflects first-order light in the collimated laser light toward the laser diode, a second optical element that reflects the zero-order light reflected by the diffraction grating in a predetermined direction while transmitting a part of the zero-order light reflected by the diffraction grating, and a first detector that detects at least one of a wavelength and an intensity of the light that passes through the second optical element.