Abstract: The present invention relates to a method for manufacturing a semiconductor substrate, including: (a) preparing an epitaxial substrate having a nitride semiconductor layer formed on a first main surface of a growth substrate and preparing a first support substrate, forming a resin adhesive layer between the first main surface of the growth substrate and a first main surface of the first support substrate, and bonding the epitaxial substrate to the first support substrate; (b) thinning a second main surface of the growth substrate; (c) forming a first protective thin film layer on the thinned growth substrate; (d) forming a second protective thin film layer on the first support substrate; (e) removing the thinned growth substrate; (f) bonding a second support substrate onto the nitride semiconductor layer; and (g) removing the first support substrate and the resin adhesive layer.

Abstract: A semiconductor laser device includes semiconductor laser elements emitting laser beams having different wavelengths from each other and a partial reflection element. The semiconductor laser elements and the partial reflection element constitute respective ends of an external resonator. Further, there is a transmissive wavelength dispersion element located on optical paths of the laser beams between the semiconductor laser elements and the partial reflection element and at a position where the laser beams are superimposed. The transmissive wavelength dispersion element has a wavelength dispersion property, and changes traveling directions of the laser beams in a first plane including the optical axes of the laser beams to combine the laser beams to have one optical axis. Also, there is an asymmetric refraction optical element located on an optical path between the transmissive wavelength dispersion element and the partial reflection element.

Abstract: A laser processing method that can reduce warpage occurring in a glass and reduce a stress generated on the glass at a time of releasing a protective material from the glass. The laser processing method includes: forming the protective materials on both surfaces of the glass; processing the glass by radiating a laser beam onto the glass together with the protective materials after the protective material formation; and releasing the protective materials from the glass after the laser processing.

Abstract: A semiconductor laser device, in which, between a wavelength dispersive element and a partially reflecting mirror, such an anamorphic prism pair is arranged that is configured to increase an angle formed by a regular oscillation optical axis of a regular oscillation beam emitted from each of light emitting points and a cross-coupling optical axis of a cross-coupling oscillation beam oscillating through a different one of the light emitting points. It is therefore possible to increase oscillation loss of the cross-coupling oscillation beam, thereby improving focusing properties, without increasing the device in size.

Abstract: A beam combining device causing beams from a plurality of light sources and one or a plurality of spare light sources to enter a beam combining optical system, and to be combined and output after passing through a beam combining element. The beam combining device is configured to: detect a failure in the plurality of light sources; and move at least a part of the respective light sources, the spare light source, and the beam combining optical system, to cause a beam to enter the beam combining optical system from the spare light source instead of a beam from the failed light source, and to cause the beam to be combined to beams from the plurality of light sources on an optical path after the beam combining element.

Abstract: A semiconductor laser device including an external resonator including: emitters of a semiconductor laser which output a plurality of beams having different wavelengths; a combining optical system which spatially overlaps the plurality of beams output from the semiconductor laser; a wavelength dispersive element which overlaps the overlapped plurality of beams into a single beam by wavelength dispersion; and a partial reflecting mirror which reflects a portion of the single beam and returns same to the wavelength dispersive element, wherein when the width of the wavelength dispersive element in a direction in which the single beam is separated into a plurality of beams by wavelength dispersion is taken as a wavelength dispersive element width, and when the beam upon establishment of normal oscillation is taken as a normal oscillation beam, the wavelength dispersive element width is the same size as the width of the normal oscillation beam.

Abstract: A laser processing method that can reduce warpage occurring in a glass and reduce a stress generated on the glass at a time of releasing a protective material from the glass. The laser processing method includes: forming the protective materials on both surfaces of the glass; processing the glass by radiating a laser beam onto the glass together with the protective materials after the protective material formation; and releasing the protective materials from the glass after the laser processing.

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 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 semiconductor laser apparatus, including: a beam divergence angle correction optical system for correcting a divergence angle of beams generated from light emitting points of a semiconductor laser bar; a beam rotation optical system for rotating the beams each having the corrected divergence angle; a wavelength dispersion optical element having a wavelength dispersion function; and a partial reflection mirror. A relative position of the beam divergence angle correction optical system with respect to the light emitting point in a divergence angle correction direction is changed for each light emitting point.

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 wavelength conversion crystal including: a single nonlinear optical crystal which satisfies both of a first phase-matching condition and a second phase-matching condition, the first phase-matching condition being required for first wavelength conversion to convert a fundamental wave having a wavelength of 1064 nm into a second harmonic having a wavelength of 532 nm, and the second phase-matching condition being required for second wavelength conversion to convert the light having a wavelength of 532 nm into a fourth harmonic having a wavelength of 266 nm; and a first reflective face and a second reflective face for reflecting the light having a wavelength of 532 nm generated by the first wavelength conversion to supply it to the second wavelength conversion. This approach can efficiently generate a third or higher-order harmonic with a reliable and simple configuration.

Abstract: A semiconductor laser apparatus, including: a beam divergence angle correction optical system for correcting a divergence angle of beams generated from light emitting points of a semiconductor laser bar; a beam rotation optical system for rotating the beams each having the corrected divergence angle; a wavelength dispersion optical element having a wavelength dispersion function; and a partial reflection mirror. A relative position of the beam divergence angle correction optical system with respect to the light emitting point in a divergence angle correction direction is changed for each light emitting point.

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 wavelength conversion crystal including: a single nonlinear optical crystal which satisfies both of a first phase-matching condition and a second phase-matching condition, the first phase-matching condition being required for first wavelength conversion to convert a fundamental wave having a wavelength of 1064 nm into a second harmonic having a wavelength of 532 nm, and the second phase-matching condition being required for second wavelength conversion to convert the light having a wavelength of 532 nm into a fourth harmonic having a wavelength of 266 nm; and a first reflective face and a second reflective face for reflecting the light having a wavelength of 532 nm generated by the first wavelength conversion to supply it to the second wavelength conversion. This approach can efficiently generate a third or higher-order harmonic with a reliable and simple configuration.

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.