Light-source unit

摘要

A light source unit for receiving and transmitting information to and from an optical disk or the like, which reshapes an elliptical in cross-section beam of laser light into a circular in cross-section beam of laser light by a beam shaping assembly composed of at least one lens having a cylindrical surface and an optical axis, the cylindrical surface having generatrix lines that are perpendicular to the optical axis of the lens, where the circularly shaped beam of laser light then enters a wavelength converter for generation of a second harmonic (half wavelength of the fundamental).