摘要:
The present invention relates to an apparatus (1) for reading from and/or writing to a multilayer holographic storage medium (12) with a coaxial arrangement of a reference beam (2a) and an object beam (2b) or a reconstructed object beam (2c). The apparatus (1) has an objective lens (11) for focusing the reference beam (2a) into the multilayer holographic storage medium (12). According to the invention the reference beam (2a) has a focal point behind or before a reflective layer (13) of the multilayer holographic storage medium (12).
摘要:
The present invention relates to a holographic recording medium (9) with an improved servo structure. The holographic recording medium (9) has a hologram layer (96) for storing holograms and a servo layer (92) for positioning a light beam for reading and/or recording of a hologram relative to the holographic recording medium. The servo layer (92) is an essentially flat dye recording layer (98). A holographic pickup (1) for use with such a holographic recording medium (9) includes a light source (13) for generating a light beam (14), which interacts with the dye recording layer (98) for recording servo information (99).
摘要:
The present invention relates to an apparatus (1) for reading from holographic storage media (13) using a homodyne detection scheme. According to the invention, the apparatus (1) for reading from a holographic storage medium (13), with a light source (2') for generating a reference beam (5) and a local oscillator beam (20), and an objective lens (12) for focusing the reference beam (5) into the holographic storage medium in order to generate a reconstructed object beam (14). The coherence length of the reference beam (5) and the local oscillator beam (20) is shorter than twice the distance between the objective lens (12) and the holographic storage medium (13).
摘要:
The present invention relates to an optical recording medium (16) and to an apparatus (1) and a method for reading from the optical recording medium (16). The optical recording medium (16) is provided with one or more polarization rotating films (32, 36). An apparatus for reading from the optical recording medium (16) includes a light source (2) for generating a polarized light beam (3, 6, 7) and one or more variable polarization rotating elements (19, 30), which are located in an optical path of the light beam (3, 6, 7) before the optical recording medium (16) .
摘要:
The present invention relates to an apparatus (1) and a method for reading from holographic storage media (13), and more specifically to an apparatus (1) and a method for reading from holographic storage media (13) with reduced noise. According to the invention, a light source (2) is provided for generating at least a reference beam (5), and an objective lens (12) for focusing the reference beam (5) into the holographic storage medium in order to generate a reconstructed object beam (14). One or more optical elements (12, 15) within the optical path of the reference beam (5) or the reconstructed object beam are mounted on at least one mechanical modulator (32), which oscillates with an oscillation frequency.
摘要:
The present invention relates to a holographic recording medium (9) with an improved servo structure. The holographic recording medium (9) has a hologram layer (96) for storing holograms and a servo layer (92) for positioning a light beam for reading and/or recording of a hologram relative to the holographic recording medium. The servo layer (92) is an essentially flat dye recording layer (98). A holographic pickup (1) for use with such a holographic recording medium (9) includes a light source (13) for generating a light beam (14), which interacts with the dye recording layer (98) for recording servo information (99).