摘要:
An optical pickup for recording a hologram by using an angle multiplexing method. An optical beam is separated into two beams, a signal beam and a reference beam having different convergence/divergence degrees, by using an optical component such as a diffraction lens. The signal and reference beams are made incident upon the same objective, and the optical component or the objective lens is moved in a direction perpendicular to an optical axis, to thereby realize angle multiplex recording. If an optical information recording medium is inclined, the optical component or the objective lens is moved along the direction along which the optical information recording medium moved to change an angle of the reference beam incident upon the optical information recording medium and compensate for degradation of a reproduction signal.
摘要:
An optical pickup for recording a hologram by using an angle multiplexing method. An optical beam is separated into two beams, a signal beam and a reference beam having different convergence/divergence degrees, by using an optical component such as a diffraction lens. The signal and reference beams are made incident upon the same objective, and the optical component or the objective lens is moved in a direction perpendicular to an optical axis, to thereby realize angle multiplex recording. If an optical information recording medium is inclined, the optical component or the objective lens is moved along the direction along which the optical information recording medium moved to change an angle of the reference beam incident upon the optical information recording medium and compensate for degradation of a reproduction signal.
摘要:
A holographic recording medium in which information can be reproduced by phase conjugate beam without requiring a mirror for obtaining the phase conjugate beam and its driving part and recording density is not reduced. The recording medium includes a recording layer in which an interference pattern is recorded and a light absorption/transmission layer which can be reversibly changed to be in a first state where signal beam and reference beam passed through the recording layer are absorbed at the time of recording of information and a second state where the reference beam is transmitted at the time of reproduction of information, and the reference beam transmitted through the light absorption/transmission layer is reflected by a reflection layer to produce the phase conjugate beam.
摘要:
In an information recording apparatus using a hologram, a signal area of the light flux to be recorded is secured to be as wide as possible and the optical power loss is depressed during reproduction process. For this reason, almost the entire surface of the spatial light modulator is allocated as a signal area and the reference beam is collected on a micro mirror placed on its optical axis.
摘要:
A holographic recording medium in which information can be reproduced by phase conjugate beam without requiring a mirror for obtaining the phase conjugate beam and its driving part and recording density is not reduced. The recording medium includes a recording layer in which an interference pattern is recorded and a light absorption/transmission layer which can be reversibly changed to be in a first state where signal beam and reference beam passed through the recording layer are absorbed at the time of recording of information and a second state where the reference beam is transmitted at the time of reproduction of information, and the reference beam transmitted through the light absorption/transmission layer is reflected by a reflection layer to produce the phase conjugate beam.
摘要:
The compatible type optical pickup device is capable of recording and reproducing optical disks in different disk substrate thickness such as BD and HD DVD or the like. In more detail, an optical pickup can record and reproduce the media of two or more kinds in different substrate thickness using almost identical wavelength or the identical laser source. One is provided as the infinite type optical system and the other is provided as the finite type optical system using an expander lens. Accordingly, the optical disks of different substrate thickness such as BD and HD DVD can be recorded and reproduced with compatibility using the identical wavelength of light.
摘要:
Disclosed here is a method for solving a conventional problem that no spherical aberration signal can be detected from any push-pull signal that is easy to adjust an object photodetector when a differential push-pull signal is obtained. To achieve the above object, sub-beams used to detect a differential push-pull signal are defocused from the main beam and spherical aberration signals are detected and the compensation of the spherical aberration is started while tracking controlling is off and detection of spherical aberration signals is held while the tracking controlling is on. The present invention can thus obtain both of the spherical aberration signal and the differential push-pull signal at the same time with use of the conventional detection system.
摘要:
The optical information recording and reproducing device utilizing holography requires the optical system to generate the signal beam and the reference beam to be irradiated to the holographic storage medium as well as another optical system to generate the curing light beam to be irradiated to the holographic storage medium. Furthermore, from the viewpoint of backward compatibility, if the same device is used for recording or reproduction on the conventional optical discs represented by Blu-ray Disc, another optical system adaptable to recording and reproduction on these optical disks is required. This means the optical system configurations become complicated and larger in size. One solution for downsizing is to use the reference beam also as the curing light beam. Another way is sharing of optical path for curing light beam and for the reference beam. Furthermore, it is possible to share the light source for generating the curing light beam and for generating the recording or reproducing light beam. In such way, optical system configurations become simple.
摘要:
A monocular holographic storage device or system to provide for compact recording and/or reading of data pages in a holographic storage medium. Also provided are methods for carrying out such data storage and/or data recovery using a monocular holographic storage device or system. Further provided are articles including holographic storage media for recording or for reading recorded data using such devices or systems.
摘要:
A monocular holographic storage device or system to provide for compact recording and/or reading of data pages in a holographic storage medium. Also provided are methods for carrying out such data storage and/or data recovery using a monocular holographic storage device or system. Further provided are articles including holographic storage media for recording or for reading recorded data using such devices or systems.