| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a compact apparatus for RECORDING and/or writing to holographic recording medium and a filter 17 for use in such an apparatus. <P>SOLUTION: A polarizing filter 17 for a light beam has a substrate with an outer zone 17a and an inner zone 17b and in which the outer zone 17a and the inner zone 17b have different optical properties for a first direction of polarization and a second direction of polarization and a wave plate 17c attached to the substrate for influencing the polarization of the light bean, wherein a part of the wave plate 17c corresponding to either the outer zone 17a or the inner zone 17b is switchable. <P>COPYRIGHT: (C)2008,JPO&INPIT |
