Abstract: A crystal orientation detecting apparatus for detecting a crystal orientation of a nonlinear optical crystal substrate includes a laser beam applying unit applying a linearly polarized laser beam to a surface of the nonlinear optical crystal substrate, a harmonic detecting unit detecting a harmonic produced from the nonlinear optical crystal substrate due to a nonlinear optical effect, a recording unit recording the relationship between the angular displacement through which the plane of polarization of the laser beam and the nonlinear optical crystal substrate are rotated relatively to each other, and the intensity of the harmonic, and a crystal orientation detecting unit detecting the crystal orientation of the nonlinear optical crystal substrate based on the recorded relationship.

Abstract: A crystal orientation detecting apparatus for detecting a crystal orientation of a nonlinear optical crystal substrate includes a laser beam applying unit applying a linearly polarized laser beam to a surface of the nonlinear optical crystal substrate, a harmonic detecting unit detecting a harmonic produced from the nonlinear optical crystal substrate due to a nonlinear optical effect, a recording unit recording the relationship between the angular displacement through which the plane of polarization of the laser beam and the nonlinear optical crystal substrate are rotated relatively to each other, and the intensity of the harmonic, and a crystal orientation detecting unit detecting the crystal orientation of the nonlinear optical crystal substrate based on the recorded relationship.

Abstract: A method of processing a plate-shaped work-piece with a laser beam so as to be divided along a plurality of projected dicing lines on the workpiece includes: forming a plurality of first shield tunnels, each including fine pores and an amorphous substance surrounding the fine pores, in the workpiece along the projected dicing lines by applying a pulsed laser beam having a wavelength transmittable through the workpiece to the workpiece along the projected dicing lines while positioning a converged zone of the pulsed laser beam within the workpiece; changing the converged zone of the pulsed laser beam to be applied to the workpiece to a position along thicknesswise directions of the workpiece; and, forming a plurality of second shield tunnels in the workpiece adjacent and parallel to the first shield tunnels along the direction in which the pulsed laser bream is applied.