Optical pickup

摘要

An optical pickup has a light source that emits a light beam having a far field pattern being elliptical in cross section; a collimator lens that converts the light beam from the light source into a substantially parallel light beam; a beam shaping element that performs beam shaping by changing a substantial aspect ratio of the far field pattern of the light beam from the collimator lens; light condensing means of condensing the light beam shaped by the beam shaping element on an optical information recording medium; and light detecting means of detecting a light beam reflected at the optical information recording medium. wherein the beam shaping element makes the cross section of the light beam having been shaped close to a circle by compressing the light beam substantially in a direction of a major axis of the elliptical cross section of the far field pattern, and reflects the light beam from the collimator lens to the light condensing means.