Optical disk system, optical head device, and beam reshaping device

摘要

A beam reshaping device includes first and second beam converting units having beam converging powers different in two orthogonal directions. The first and second beam converting units are arranged such that conjugate points correspond to each other in the two orthogonal directions, thereby reshaping the sectional form of a laser beam emitted from a laser light source, while effectively preventing occurrence of astigmatism. The beam reshaping device may be applied to an optical head device and which in turn may be used in an optical disk system.