Optical information storage apparatus having cylindrical lens for eliminating astigmatism generated by polarization beam splitter and newly generating astigmatism

摘要

An optical information storage apparatus is constructed to include a light source, a polarization beam splitter reflecting a light beam emitted from the light source and irradiating a reflected light beam on a recording surface of a recording medium, a first part for eliminating a coma aberration which is generated due to a light beam which is reflected by the recording surface and passes through the polarization beam splitter, a second part for eliminating an astigmatism which is generated by the polarization beam splitter and the first part, and a third part for generating an astigmatism.