摘要:
The present invention relates to a compact apparatus for reading from and/or writing to holographic storage media, and to a filter (17) for use in such an apparatus. According to the invention, a polarizing filter (17) for a light beam has: - a substrate with an outer zone (17a) and an inner zone (17b), the outer zone (17a) and the inner zone (17b) having 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 beam, wherein a part of the wave plate (17c) corresponding to either the outer zone (17a) or the inner zone (17b) is switchable.
摘要:
The present invention relates to a beam shifting element (9) and to an apparatus for reading from and/or writing to optical storage media (11) using in such a beam shifting element (9). According to the invention, the beam shifting element (9) has at least a first optical element (91, 91', 92") for deflecting an incoming light beam (7, 8) by a first angle (+A) and a second optical element (92, 92', 92") for deflecting the light beam (7, 8) coming from the first optical element (91, 91', 91") by a second angle (-A) opposite to the first angle (+A), wherein the path length of the light beam (7, 8) between the first optical element (91, 91', 91") and the second optical element (92, 92', 92") is adjustable.
摘要:
The device comprises directing means (8a, 8b, 11) for directing a first and a second light beam (7, 6) onto a hologram area (10) of the optical data carrier (1), wherein the first and second light beams (7, 6) are coherent light beams. The directing means (8a, 8b, 11) are adapted to direct the first light beam (7) onto the hologram area (10) along a first direction, and the second light beam (6) onto the hologram area (10) along a second direction. Tilting means (12) are provided for tilting the second direction by a predefined tilt angle with respect to the first direction.