Abstract: According to a positioning method for a hologram in a disk-type holographic storage medium, a guide groove is formed in advance in the disk-type storage medium and is scribed with a positioning marker that includes index information, position information and crossing angle information. The positions of a positioning laser beam and a recording/reproducing laser beam are applied to the same medium position. When an optical head accesses a recording/reading position at a high speed, the shift multiplex recording/reading is performed starting from a marker position. A servo system controls the laser beams to move along the guide groove and ensures that a focused beam is focused on the medium. According to the method, the position and angular information can be quickly positioned in process of performing cross-shift multiplex recording/reading, the recording/reading speed of the system is improved, and random access is achieved.

Abstract: The present invention relates to a holographic data storage device with a single-arm structure, and belongs to the technical field of optical holographic storage. According to the device disclosed in the present invention, a part of a reference arm and a part of a signal arm are integrated together to form a single-arm structure, which can not only reduce the number of optical and mechanical elements, but also reduce the system volume and cost without degrading performance. In addition, a signal beam and a reference beam share the same relay lens, so that the impact of environmental interference on the two beams is equal, and the stability of the entire system is improved.

Abstract: A holographic multiplexed recording method for increasing storage capacity is disclosed. In a holographic recording and reproducing device, the moving direction of a storage medium is not coplanar with the plane where the optical axes of signal light and reference light are located, or the relative moving direction of the storage medium and the signal light or the reference light is not coplanar with the plane where the optical axes of the signal light and the reference light are located. Through the method, a certain angle exists between the grating vector direction and the moving direction or the relative moving direction, so that the phenomenon that the grating vector directions are the same does not occur when the medium is subjected to multiplexed recording after being rotated or flipped. Not only is multiplexing number increased, but also crosstalk caused by the same grating vector direction is prevented.

Abstract: The present invention relates to the technical field of holographic multiplexing storage, and in particular, to a multiplexing method for increasing storage capacity in a disc-type holographic storage medium. According to the method disclosed by the present invention, holograms with different grating vector directions can be overwritten and recorded in the same storage medium according to Bragg selection characteristics of volume holographic records, and the obtained holograms do not affect each other. According to the method disclosed by the present invention, on the premise of ensuring low crosstalk between data pages, the multiplexing number of shift multiplexing storage is increased by using a cross-shift multiplexing method, and the storage density is improved.