Abstract: A laser processing device including: a laser oscillator; a processing table; a transmission optical system for transmitting laser light emitted from the laser oscillator to the processing table; a processing head for condensing and radiating the laser light transmitted via the transmission optical system to an object to be processed; a moving mechanism for changing a relative position between the object to be processed and the laser light to be radiated to the object to be processed; and a variable curvature spherical mirror. The transmission optical system includes a reflective beam expander mechanism for collimating and magnifying the laser light from the laser oscillator. The reflective beam expander mechanism includes a spherical mirror and a concave mirror having different curvatures in two orthogonal axes.

Abstract: A gas laser device which can perform optical amplification, laser light passing through a laser gas excited by electrical discharge, including: a first and second pair of discharge electrodes arranged longitudinally along an optical axis of the laser light; at least two mirrors reflecting the laser light amplified by the gas laser, the mirrors arranged opposite to each other to interpose a first discharge region defined by the first pair of discharge electrodes and a second discharge region defined by the second pair of discharge electrodes therebetween; and a shielding member located between the first pair of discharge electrodes and the second pair of discharge electrodes, the shielding member protruding from electrode surfaces of the discharge electrodes toward the optical axis of the laser light. The configuration can efficiently suppress parasitic oscillation with a simple structure.

Abstract: A laser machining apparatus, including: a laser light source; a transparent member that is set on an optical path of a laser beam and transmits the laser beam; a contact type temperature difference sensor, set on a surface of the transparent member outside an irradiation range of the laser beam, for detecting a temperature difference between a surface of the transparent member, which is spaced apart from a center of the transparent member by a first distance, and another surface of the transparent member, which is spaced apart from the center of the transparent member by a second distance larger than the first distance; and a controller correcting a focal position based on the temperature difference detected by the contact type temperature difference sensor to stabilize a beam diameter of the laser beam condensed onto a machining object.

Abstract: A laser processing device including: a laser oscillator; a processing table; a transmission optical system for transmitting laser light emitted from the laser oscillator to the processing table; a processing head for condensing and radiating the laser light transmitted via the transmission optical system to an object to be processed; a moving mechanism for changing a relative position between the object to be processed and the laser light to be radiated to the object to be processed; and a variable curvature spherical mirror. The transmission optical system includes a reflective beam expander mechanism for collimating and magnifying the laser light from the laser oscillator. The reflective beam expander mechanism includes a spherical mirror and a concave mirror having different curvatures in two orthogonal axes.

Abstract: A laser oscillator includes: a optical resonator having an orthogonal mirror and a partial reflection mirror; a laser gas acting as a laser medium; and a 90-degree folding mirror acting as a polarization selecting element. The orthogonal mirror has two reflecting surfaces orthogonal to each other. The 90-degree folding mirror is arranged such that the polarization direction of the laser oscillated light is parallel to the reference axis set in a plane perpendicular to an optical axis of the optical resonator. The orthogonal mirror is arranged such that the polarization direction of the laser oscillated light is parallel to the valley line of the orthogonal mirror. This configuration can compensate anisotropy of optical characteristics in a laser medium, and stably generate linearly polarized laser light having excellent isotropy in a simple manner.

Abstract: A CO2 gas laser device according to the present invention amplifies CO2 laser light that oscillates repeatedly in short pulses having a pulse width of 100 ns or less, and cools a CO2 laser gas which is excited by continuous discharge by circulating the CO2 laser gas by means of forced convection. Therein, an angle ? defined by the optical axis of the amplified CO2 laser beam and the flow direction of the CO2 laser gas caused by the forced convection is determined by both a discharge cross sectional area and a discharge length of a volume in which the CO2 laser gas is excited by discharge, whereby increasing the gain of pulsed laser to achieve pulsed laser light having an extremely high average output power.

Abstract: A tri-axially orthogonal gas laser device in which an optical axis of an optical resonator, a direction in which a laser gas is supplied into the optical resonator, and a direction of discharge for exciting the laser gas are mutually orthogonal to one another, the device including: an exciting unit including a blower supplying the laser gas in ?X direction to the optical axis of the optical resonator, and a discharge electrode pair which is shifted on a gas upstream side with respect to the optical axis; and an exciting unit including a blower for supplying the laser gas in +X direction to the optical axis of the optical resonator, and a discharge electrode pair which is shifted on a gas upstream side with respect to the optical axis

Abstract: A CO2 gas laser device according to the present invention amplifies CO2 laser light that oscillates repeatedly in short pulses having a pulse width of 100 ns or less, and cools a CO2 laser gas which is excited by continuous discharge by circulating the CO2 laser gas by means of forced convection. Therein, an angle ? defined by the optical axis of the amplified CO2 laser beam and the flow direction of the CO2 laser gas caused by the forced convection is determined by both a discharge cross sectional area and a discharge length of a volume in which the CO2 laser gas is excited by discharge, whereby increasing the gain of pulsed laser to achieve pulsed laser light having an extremely high average output power.

Abstract: A laser machining apparatus, including: a laser light source; a transparent member that is set on an optical path of a laser beam and transmits the laser beam; a contact type temperature difference sensor, set on a surface of the transparent member outside an irradiation range of the laser beam, for detecting a temperature difference between a surface of the transparent member, which is spaced apart from a center of the transparent member by a first distance, and another surface of the transparent member, which is spaced apart from the center of the transparent member by a second distance larger than the first distance; and a controller correcting a focal position based on the temperature difference detected by the contact type temperature difference sensor to stabilize a beam diameter of the laser beam condensed onto a machining object.

Abstract: A tri-axially orthogonal gas laser device in which an optical axis of an optical resonator, a direction in which a laser gas is supplied into the optical resonator, and a direction of discharge for exciting the laser gas are mutually orthogonal to one another, the device including: an exciting unit including a blower supplying the laser gas in ?X direction to the optical axis of the optical resonator, and a discharge electrode pair which is shifted on a gas upstream side with respect to the optical axis; and an exciting unit including a blower for supplying the laser gas in +X direction to the optical axis of the optical resonator, and a discharge electrode pair which is shifted on a gas upstream side with respect to the optical axis

Abstract: An image-scanning device wherein plural images of an object are picked up inverted and reduced in size by image-forming optical systems arranged to be adjacent to each other, and then restored by an image processing system. Each optical system includes a first optical element having a first focal length; an aperture member located at a focus position in a rear side of the first optical element; and a second optical element provided in a rear side of the aperture member and having a second focal length shorter than the first focal length, respectively disposed from a side of the object being picked up to a side of the image pickup device. In between optical systems, corresponding image pick up devices thereof are arranged to be adjacent to each other, the image pickup devices including a region in which the images picked up by the image pickup devices are overlapped.

Abstract: A laser oscillator includes: a optical resonator having an orthogonal mirror and a partial reflection mirror; a laser gas acting as a laser medium; and a 90-degree folding mirror acting as a polarization selecting element. The orthogonal mirror has two reflecting surfaces orthogonal to each other. The 90-degree folding mirror is arranged such that the polarization direction of the laser oscillated light is parallel to the reference axis set in a plane perpendicular to an optical axis of the optical resonator. The orthogonal mirror is arranged such that the polarization direction of the laser oscillated light is parallel to the valley line of the orthogonal mirror. This configuration can compensate anisotropy of optical characteristics in a laser medium, and stably generate linearly polarized laser light having excellent isotropy in a simple manner.

Abstract: The machining device is equipped with a fiber laser oscillator for oscillating laser light of a top hat shape, and a light collecting lens and a machining head for collecting the laser light of the top hat shape and emitting the laser light onto a machining target such that the beam diameter of the laser light of the top hat shape at a position where light intensity becomes the one corresponding to a machining threshold of the machining target is about three times the size of the beam diameter of laser light in a Gaussian mode at the same position, when the laser light in the Gaussian mode has a beam quality substantially the same as that of the laser light of the top hat shape.

Abstract: An optical wavelength conversion element includes a cesium-lithium-borate crystal processed into a 10-mm long optical element cut in an orientation that allows a fourth harmonic of a Nd:YAG laser to be generated. A transmittance (Ta) at 3589 cm?1 in an infrared transmission spectrum of the optical element is used as an index that indicates a content of water impurities in the crystal and is independent of a polarization direction. An actual measurement of the transmittance Ta is at least 1%, without taking into account loss at an optically polished surface of the crystal. A wavelength conversion device, a ultraviolet laser irradiation apparatus, a laser processing system, and a method of manufacturing an optical wavelength conversion element are also described.

Abstract: An image-scanning device having a large depth of field and being small in size. The image-scanning device includes a plurality of cells and an image pickup device that is located so as to correspond to the cells and that picks-up the formed images. Each cell includes a first lens having a first focal length; an aperture member located at the first focal length from the first lens; and a second lens located at a second focal length shorter than the first focal length, with respect to the image pickup device.

Abstract: A laser machining device includes a laser oscillator, a laser machining head, an optical fiber transmitting the laser beam oscillated by the laser oscillator to the laser machining head, and an assist gas supply supplying an assist gas of oxygen to the laser machining head. The optical fiber includes a remover removing a clad transmitting beam or reducer for reducing the beam. The laser beam leaked from the core of the optical fiber into the clad is absorbed by a beam absorber at the remover. The structure ensures a high quality surface with no irregularity on the metal surface cut by the laser beam projected from the machining head.

Abstract: An optical wavelength conversion element includes a cesium-lithium-borate crystal processed into a 10-mm long optical element cut in an orientation that allows a fourth harmonic of a Nd:YAG laser to be generated. A transmittance (Ta) at 3589 cm?1 in an infrared transmission spectrum of the optical element is used as an index that indicates a content of water impurities in the crystal and is independent of a polarization direction. An actual measurement of the transmittance Ta is at least 1%, without taking into account loss at an optically polished surface of the crystal. A wavelength conversion device, a ultraviolet laser irradiation apparatus, a laser processing system, and a method of manufacturing an optical wavelength conversion element are also described.

Abstract: A simple and high-reliability constitution provides a solid-state laser system that allows a high-output, long-pulse-width laser beam to be obtained. A solid-state laser system that includes a solid-state laser medium 1, a light source 2 for pumping the solid-state laser medium 1, two reflecting mirrors 3 and 4 for flanking the solid-state laser medium 1, thereby constituting a laser resonator, is constituted in such a manner that a virtual-mirror plane 5 is defined in the space between the solid-state laser medium 1 and the reflecting mirror 4; a lens 6 is provided between the virtual-mirror plane 5 and the reflecting mirror 4; and, by means of the forward and backward paths along the route from the virtual-mirror plane to the reflecting mirror by way of the lens, the virtual-mirror plane in the forward path and the virtual-mirror plane in the backward path are made in an optically conjugated relationship with each other.

Abstract: A fundamental laser beam is wavelength converted through nonlinear optical crystals by traveling in one direction, sequentially through two nonlinear optical crystals arranged in series. A wavelength-converted laser beam is generated and includes wavelength-converted laser beams having polarized directions differing from each other by angles in a range from 45° to 90°. The two nonlinear optical crystals have crystal orientation axes differing by 45° to 90° when viewed along the optical axis of the laser beam.

Abstract: A wavelength conversion apparatus in which output direction of a wavelength-converted laser beam, having a wavelength converted by a nonlinear optical crystal and emitted through an output-window, can be brought close to the direction of optical axis of the laser beam passing through the nonlinear optical crystal. In addition, axial deviation of the wavelength-converted laser beam converted by the nonlinear optical crystal and emitted through an output-window, can be reduced when the position of the nonlinear optical crystal is moved. The output facet of the nonlinear optical crystal is inclined at Brewster's angle with respect to the wavelength-converted laser beam. An output-window of a case containing the nonlinear optical crystal has a prism form in which the distance between a laser beam input facet and a laser beam output facet of the output-window is reduced along a direction in which the wavelength-converted laser beam, emitted from the nonlinear optical crystal, inclines.