Method for holographic storage using peristrophic multiplexing

A method of multiplexing holograms by rotating the material or, equivalently, the recording beams is described. Peristropic (Greek for rotation) multiplexing can be combined with other multiplexing methods to increase the storage density of holographic storage systems. Peristrophic multiplexing is experimentally demonstrated with Du Pont's HRF-150 photopolymer film. We multiplexed a total of 295 holograms in a 38-μm-thick photopolymer film by combining peristrophic multiplexing with angle multiplexing

Storage Density of Shift-Multiplexed Holographic Memory

The storage density of shift-multiplexed holographic memory is calculated and compared with experimentally achieved densities by use of photorefractive and write-once materials. We consider holographic selectivity as well as the recording material s dynamic range (M /#) and required diffraction efficiencies in formulating the calculations of storage densities, thereby taking into account all major factors limiting the raw storage density achievable with shift-multiplexed holographic storage systems. We show that the M /# is the key factor in limiting storage densities rather than the recording material s thickness for organic materials in which the scatter is relatively high. A storage density of 100 bits m2 is experimentally demonstrated by use of a 1-mm-thick LiNbO3 crystal as the recording medium

Optical detection of asymmetric bacteria utilizing electro orientation

We propose a bacterial detection scheme which uses no biochemical markers and can be applied in a Point-of-Care setting. The detection scheme aligns asymmetric bacteria with an electric field and detects the optical scattering

Holographic storage using shift multiplexing

We demonstrate theoretically and experimentally a new multiplexing method for volume holographic storage using a single reference beam that is composed of multiple plane waves or is a spherical wave. We multiplex the holograms by shifting the recording material or the recording/readout head. The volume properties of the recording medium allow selective readout of holograms stored in successive overlapping locations. High storage densities can be achieved with a relatively simple implementation by use of the new method

Experimental demonstration of a holographic memory with a surface density of 100 bits/(µm^2)

The next generation compact disc due in early 1997, the Digital-Video-Disc (DVD), will have a capacity of ~6 Gbytes per layer, for a maximum planned capacity of ~20 Gbytes per double-sided disk with two layers on each side. That translates to a surface density of approximately 20 bits/(µm^2) for the four-layered DVD disk. In order for holographic three-dimensional disks to be competitive, we must demonstrate a much higher surface density than the most advanced DVD

High-density storage in holographic 3D disks

We have achieved a surface density of 10 bits/µm^2 (6.5 Gbits/in^2) with an experimental holographic storage setup, using DuPont's 100 µm thick photopolymer as the recording medium. Its performance characteristics in terms of access rate and signal-to- noise-ratio are described. Furthermore, a simple holographic 3D disk system with high surface density (10 bits/µm^ using a 100 µm thick recording material) and an architecture similar to compact disks is shown

Real-time vehicle navigation using a holographic memory

We describe an optoelectronic information processing system that is capable of real-time vehicle navigation and target acquisition. The system uses a holographic database, based on the DuPont HRF-150 photopolymer, to perform the desired tasks. The architecture and the performance of the system are discussed in detail

Exposure schedule for multiplexing holograms in photopolymer films

An iterative method is introduced for determining the exposure schedule for multiplexing holograms in saturable recording materials, such as photopolymers. This method is designed to share all or part of the available dynamic range of the recording material among the holograms to be multiplexed. Using exposure schedules derived from this method, the authors find that the diffraction efficiency of DuPont’s HRF‐150 38‐ and 100‐μm photopolymer scale is (2.2/M)^2 and (6.5/M)^2 respectively, where M is the number of holograms recorded. Finally, 1000 holograms were multiplexed at a single location in the 100‐μm thick photopolymer using an exposure schedule derived with this method

Holographic optical disc

The holographic disc is a high capacity, disk-based data storage device that can provide the performance for next generation mass data storage needs. With a projected capacity approaching 1 terabit on a single 12 cm platter, the holographic disc has the potential to become a highly efficient storage hardware for data warehousing applications. The high readout rate of holographic disc makes it especially suitable for generating multiple, high bandwidth data streams such as required for network server computers. Multimedia applications such as interactive video and HDTV can also potentially benefit from the high capacity and fast data access of holographic memory

4-Chloro-N-(3-phenyl­allyl­idene)aniline

In the title mol­ecule, C15H12ClN, the C=N and C=C bond lengths are 1.273 (2) and 1.324 (2) Å, respectively. The two aromatic rings form a dihedral angle of 3.27 (3)°