Patent ID: 8018813
Filing Date: 2011-09-13
Classification: G11B

Abstract:
1. A holographic information recording and/or reproducing apparatus to record and/or reproduce information to/from a holographic information storage medium, the holographic information recording and/or reproducing apparatus comprising: a first light source unit to emit a reference light and a signal light in a recording mode, each being linear polarized light and orthogonal to each other; a first optical path guiding unit to guide the reference light and the signal light emitted by the first light source unit so that the reference light and the signal light cross each other at a first crossing point after passing through different optical paths; a second optical path guiding unit comprising a first polarization converter located on an optical path of the reference light or the signal light before the first crossing point, a first polarization beam splitter located at the first crossing point of the reference light and the signal light, at least one first optical path converter to guide the reference light and/or the signal light so that the reference light and the signal light cross again at a second crossing point after the first crossing point, a second polarization converter located on the optical path of the signal light before the second crossing point after passing through the first polarization beam splitter, and a second polarization beam splitter located at the second crossing point to unite the optical paths of the reference light and the signal light; and an objective lens unit to illuminate the reference light and the signal light that have passed through the second polarization beam splitter onto a single side of the holographic information storage medium.