Abstract: A laser processing apparatus includes: a light source device configured to emit a laser beam; a laser head having a lens and being configured to converge through the lens a laser beam emitted from the light source device and to irradiate a target object with the converged laser beam; a wobbling mechanism configured to wobble a laser beam spot formed on the target object, the laser beam spot having an elliptical shape with a major axis and a minor axis; and a control device configured to control the wobbling mechanism under a wobble mode in which a first wobble frequency along the major axis direction of the laser beam spot is higher than a second wobble frequency along the minor axis direction of the laser beam spot.

Abstract: Provided is a polarization state converting element including a plurality of waveplates, and a rotation mechanism that rotates the respective waveplates independently of one another around an optical axis. The waveplates are each configured by a substrate made of a material having no optical rotatory property but having birefringence, or are each made of a material having neither optical rotatory property nor birefringence, but having transparency, a function of phase delay depending on polarization being applied on a surface of each waveplate.

Abstract: Provided is a polarization state converting element including a plurality of waveplates, and a rotation mechanism that rotates the respective waveplates independently of one another around an optical axis. The waveplates are each configured by a substrate made of a material having no optical rotatory property but having birefringence, or are each made of a material having neither optical rotatory property nor birefringence, but having transparency, a function of phase delay depending on polarization being applied on a surface of each waveplate.