Allen Pu

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 Ponts HRF-150 photopolymer film. We multiplexed a total of 295 holograms in a 38-microm-thick photopolymer film by combining peristrophic multiplexing with angle multiplexing.

High-density recording in photopolymer-based holographic three-dimensional disks.

The performance specifications of a holographic three-dimensional disk system are experimentally characterized. A surface density of 10 bits/µm(2) is experimentally demonstrated with a 100-µm-thick photopolymer as the recording medium.

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.

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.

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 materials 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 materials thickness for organic materials in which the scatter is relatively high. A storage density of 100 bits/mum(2) is experimentally demonstrated by use of a 1-mm-thick LiNbO(3) 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 3D disks using shift multiplexing

Summary form only given. Recently, we demonstrated holographic recording in a 100-micron-thick photopolymer, achieving a surface density of 10 bits//spl mu/m/sup 2/, by recording a combination of peristrophic and angle-multiplexed holograms. We would like to further increase the capacity of this system by storing data at many different locations. One simple implementation of such system would be a holographic 3-D disk, where the disk spins so that holograms stored at different locations on the disk could be accessed. We will use a new multiplexing method (shift multiplexing) that is especially well suited for the holographic disk configuration.

A new method for holographic data storage in photopolymer films

Recently, photopolymer films have been developed that are inexpensive, easy to fix and have a relatively large dynamic range, making them good candidates for high density data storage. An example of this material is DuPonts HRF-150-38 photopolymer film. The storage density achievable with these materials is limited due to their thickness of tens of microns. In this paper we present two results. First, a new holographic multiplexing method (peristrophic multiplexing) that significantly increases the storage density achievable in thin films is demonstrated. In addition, an exposure schedule that maximizes the utilization of available dynamic range of the photopolymer is derived.<<ETX>>

Shift-multiplexed holographic 3D disk

Shift multiplexing is a holographic storage method implemented with spherical wave reference beams. We present the main properties of shift multiplexing, compare it with angle multiplexing, and describe the design of a holographic 3D disk system that is capable of storing 12.4 bits/micrometers 2 using this method.

Bacteria detection in a microfluidic channel utilizing electromagnetic cellular polarization and optical scattering

A bacterial detection scheme based on aligning the bacteria with an electric field and detecting the optical scattering is examined. This method uses no biochemical markers and can be applied in a point-of-care setting