US Patent 10300558 Laser processing machine and laser cutting method

A laser processing machine includes a laser oscillator. The laser oscillator excites a laser beam having a wavelength in a 1 μm band or a shorter wavelength band. One process fiber transmits the laser beam emitted from the laser oscillator. A focusing optical element focuses, when a workpiece is irradiated with the laser beam emitted from the process fiber, the laser beam on a plurality of spots in a unit area within a unit time, the unit area having a radius of 0.5 mm of an optical axis of the laser beam, and the unit time being a time from when the workpiece starts to melt to when the melting of the workpiece ends.