Abstract: Disclosed is a laser processing method for imparting compressive residual stress to an object along an objective area on a surface of the object by irradiating the objective area with laser light. The laser processing method includes a processing step of scanning the objective area with an irradiation spot of the laser light while increasing a moving average in intensity of the laser light per unit area.

Abstract: Disclosed is a laser processing method for imparting compressive residual stress to an object along an objective area on a surface of the object by irradiating the objective area with laser light. The laser processing method includes: a first step of expanding an area irradiated with the laser light toward a first side in the objective area; and a second step of expanding the area irradiated with the laser light toward a second side different from the first side in the objective area.

Abstract: A processed product manufacturing method includes preparing a workpiece containing metal and forming a plurality of first regions and a second region along a surface of the workpiece by the irradiation of a laser beam. The first regions are applied with a tensile residual stress. In the second region applied with a compressive residual stress, a plurality of irradiation points separated from each other in the surface of the workpiece are irradiated with the laser beam. The first regions are formed to be separated from each other and each of the first regions is surrounded by the second region when viewed from a direction orthogonal to the surface.

Abstract: A laser processing apparatus includes a light source which outputs a laser light, and a waveform control unit which controls a pulse waveform of the laser light irradiating the workpiece, in which the pulse waveform of the laser light controlled by the waveform control unit includes a main pulse and a foot pulse temporally preceding the main pulse, and a peak intensity of the foot pulse is smaller than a peak intensity of the main pulse, and a peak position of the main pulse is positioned in a retention time period of plasma generated due to an incidence of the foot pulse on the workpiece.

Abstract: A laser device includes a laser medium for amplifying seed light, a first optical system for outputting excitation light for exciting the laser medium and causing the excitation light to be incident on the laser medium and input to an excitation region of the laser medium, and a second optical system for causing the seed light of first polarization to be incident on the laser medium at an incidence angle larger than 0° with respect to the laser medium and input to the excitation region.

Abstract: Disclosed are a polyacrylate (salt) and a polyacrylate (salt) water-absorbent resin containing a tracer which can be verified back to the manufacturing process of the water-absorbent resin when dealing with various problems with the water-absorbent resin which can occur from the manufacturing process of the water-resistant resin, during the use thereof by a consumer, up until the disposal thereof. The disclosed polyacrylate (salt) and the polyacrylate (salt) water-absorbent resin have a carbon stable isotope ratio (?13C) of at least ?20‰ when measured by accelerator mass spectrometry.

Abstract: A polyacrylic acid (salt), or a polyacrylic acid (salt)-based water-absorbing resin, contains a tracer for detecting various troubles in the water-absorbing resin during the period from the production of the water-absorbing resin to the use and discard thereof by a consumer. The polyacrylic acid (salt)-based water-absorbing resin has a stable carbon isotope ratio, as determined by accelerator mass spectrometry, of less than ?20‰ and a radioactive carbon content of 1.0×10?14 or more. The polyacrylic acid (salt)-based water-absorbing resin has: a CRC of 10 [g/g] or more; an AAP of 20 [g/g] or more; an Ext of 35 wt. % or less; a content of residual monomers of 1,000 ppm or less; a PSD in which the proportion of particles having a particle diameter of 150 ?m or larger but less than 850 ?m is 90 wt. % or more; and an FSR of 0.15 [g/g/s] or more.

Abstract: A laser device includes a laser medium for amplifying seed light, a first optical system for outputting excitation light for exciting the laser medium and causing the excitation light to be incident on the laser medium and input to an excitation region of the laser medium, and a second optical system for causing the seed light of first polarization to be incident on the laser medium at an incidence angle larger than 0° with respect to the laser medium and input to the excitation region.

Abstract: A laser processing apparatus includes a light source which outputs a laser light, and a waveform control unit which controls a pulse waveform of the laser light irradiating the workpiece, in which the pulse waveform of the laser light controlled by the waveform control unit includes a main pulse and a foot pulse temporally preceding the main pulse, and a peak intensity of the foot pulse is smaller than a peak intensity of the main pulse, and a peak position of the main pulse is positioned in a retention time period of plasma generated due to an incidence of the foot pulse on the workpiece.