A laser beam applying unit of a laser processing apparatus for processing a wafer includes a laser oscillator for emitting a pulsed laser beam having a wavelength transmittable through the wafer, a beam condenser for converging the pulsed laser beam emitted from the laser oscillator onto the wafer held on a chuck table, a beam splitter assembly disposed between the laser oscillator and the beam condenser, for splitting the pulsed laser beam emitted from the laser oscillator to form at least two converged spots on the wafer that are spaced from each other in X-axis directions, and a mask assembly disposed between the laser oscillator and the beam condenser, for reducing the width of the converged spots on the wafer in Y-axis directions to keep the converged spots on the wafer within the width of the projected dicing lines on the wafer.

A laser beam applying unit of a laser processing apparatus for processing a wafer includes a laser oscillator for emitting a pulsed laser beam having a wavelength transmittable through the wafer, a beam condenser for converging the pulsed laser beam emitted from the laser oscillator onto the wafer held on a chuck table, a beam splitter assembly disposed between the laser oscillator and the beam condenser, for splitting the pulsed laser beam emitted from the laser oscillator to form at least two converged spots on the wafer that are spaced from each other in X-axis directions, and a mask assembly disposed between the laser oscillator and the beam condenser, for reducing the width of the converged spots on the wafer in Y-axis directions to keep the converged spots on the wafer within the width of the projected dicing lines on the wafer.

A method includes depositing a plurality of dopant particles within a predetermined region of a transparent material. The method also includes focusing a laser beam along an optical axis to a focal region that overlaps with at least a portion of the predetermined region. The focal region can irradiate at least a first dopant particle of the plurality of dopant particles. The method further includes adjusting a parameter of the laser beam to generate a plasma configured to form an inclusion within the transparent material. The method additionally includes scanning the focal region along a path within the transparent material to elongate the inclusion generally along the path.

A method of manufacturing a diamond substrate includes: a step of placing a laser condensing unit 190 configured to condense laser light B so as to face an upper surface 10a of a block 10 of single crystal diamond, a step of forming a modified layer 20, which includes a processing mark 21 of graphite and a crack 22b extending along a surface (111) around the processing mark 21, in a partial region of the upper surface 10a of the block 10 along the surface (111) of the single crystal diamond, along the surface (111) of the single crystal diamond at a predetermined depth from the upper surface 10a of the block 10 by radiating the laser light B on the upper surface 10a of the block 10 from the laser condensing unit 190 under predetermined conditions and condensing the laser light B inside the block 10, and moving the laser condensing unit 190 and the block 10 in a relative manner two-dimensionally, and a step of forming a cleavage plane 25 at the predetermined depth of the remaining region of the upper surface 10a of the block 10 by spontaneously propagating cleavage from the modified layer 20.

A method for manufacturing a cutting tool according to one embodiment is a method for manufacturing a cutting tool, the cutting tool including a base material and a diamond single crystal material fixed to the base material, the diamond single crystal material having a rake face, a flank face continuous with the rake face, and a cutting edge formed by a ridgeline serving as a boundary between the rake face and the flank face. The method for manufacturing a cutting tool according to one form of the present disclosure includes a flank face irradiation step of applying a laser to the diamond single crystal material along the cutting edge from a side of the flank face. The laser has a pulse width of 1×10.sup.−12 seconds or less and a peak output of less than 1 W in the flank face irradiation step.

A method for manufacturing a cutting tool according to one embodiment is a method for manufacturing a cutting tool, the cutting tool including a base material and a diamond single crystal material fixed to the base material, the diamond single crystal material having a rake face, a flank face continuous with the rake face, and a cutting edge formed by a ridgeline serving as a boundary between the rake face and the flank face. The method for manufacturing a cutting tool according to one form of the present disclosure includes a flank face irradiation step of applying a laser to the diamond single crystal material along the cutting edge from a side of the flank face. The laser has a pulse width of 1×10.sup.−12 seconds or less and a peak output of less than 1 W in the flank face irradiation step.

A method of producing a glass substrate having a hole is provided. The method includes preparing the glass substrate having a first surface and a second surface facing each other; forming a hole in the glass substrate with a laser; and annealing the glass substrate placed on a first support substrate having a thermal expansion coefficient whose difference from a thermal expansion coefficient of the glass substrate is less than or equal to 1 ppm/K, where the first support substrate is placed on a second support substrate having a thermal expansion coefficient of less than or equal to 10 ppm/K.

A laser processing device comprising: a light source configured to output laser light; a spatial light modulator configured to display a modulation pattern for modulating the laser light output from the light source; a condenser lens configured to condense the laser light modulated by the spatial light modulator, on an object; and a control unit configured to control the spatial light modulator to adjust the modulation pattern in accordance with a traveling direction of a condensing point of the laser light with respect to the object.

A facet region detection method includes a first irradiation step and a second irradiation step in which a first surface and a second surface, respectively, of an ingot are irradiated with light, and a first fluorescence detection step and a second fluorescence detection step in which distribution of the number of photons of fluorescence in the first surface and the second surface, respectively, is obtained. The facet region detection method further includes a first determination step and a second determination step in which a facet region and a non-facet region are determined in the first surface and the second surface on a basis of the number of photons of the fluorescence, and a calculation step in which an estimated position of a facet region inside the ingot is calculated based on the facet region in the first surface and the facet region in the second surface.

A facet region detection method includes a first irradiation step and a second irradiation step in which a first surface and a second surface, respectively, of an ingot are irradiated with light, and a first fluorescence detection step and a second fluorescence detection step in which distribution of the number of photons of fluorescence in the first surface and the second surface, respectively, is obtained. The facet region detection method further includes a first determination step and a second determination step in which a facet region and a non-facet region are determined in the first surface and the second surface on a basis of the number of photons of the fluorescence, and a calculation step in which an estimated position of a facet region inside the ingot is calculated based on the facet region in the first surface and the facet region in the second surface.