The Optically Programmable Gate Array (OPGA), an optical version of a conventional FPGA, benefits from a direct parallel interface between an optical memory and a logic circuit. The OPGA utilizes a holographic memory accessed by an array of VCSELs to program its logic. An active pixel sensor array incorporated into the OPGA chip makes it possible to optically address the logic in a very short time allowing for rapid dynamic reconfiguration. Combining spatial and shift multiplexing to store the configuration pages in the memory, the OPGA module can be made compact. The reconfiguration capability of the OPGA can be applied to solve more efficiently problems in pattern recognition and database search.
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.
The high data transfer rate achievable in page-oriented optical memories demands for parallel interfaces to logic circuits able to process efficiently the data. The Optically Programmable Gate Array, an enhanced version of a conventional FPGA, utilizes a holographic memory accessed by an array of VCSELs to program its logic. Combining spatial and shift multiplexing to store the configuration pages in the memory, the OPGA module is very compact and has extremely short configuration time allowing for dynamic reconfiguration. The reconfiguration capability of the OPGA can be applied to solve more efficiently problems in pattern recognition and digit classification.
Reconfigurable processors bring a new computational paradigm where the processor modifies its structure to suit a given application, rather than having to modify the application to fit the device. The Optically Programmable Gate Array, an enhanced version of a conventional FPGA, utilizes a holographic memory accessed by an array of VCSELs to program its logic. Combining spatial and shift multipexing to store the configuration pages in the memory, the OPGA module is very compact and has extremely short configuration time allowing for dynamic reconfiguration. The reconfiguration capability of the OPGA can be applied to solve more efficiently problems in pattern recognition and digit classification.
The issue of interfacing holographic memory with an electronic processor is discussed. The high speed and parallel access of 2D, page formatted optical data from holographic memory can be utilized to reconfigure an electronic processor at a rate much faster than traditionally available. This new technique could be the stepping stone to a new class of high performance device for a variety of image/signal processing tasks. We will first give a review of the holographic memory activity at Holoplex, in particular, our research on holographic optical disk as a read-only memory device. We will then discuss the optical architecture for interfacing an optical ROM with a programmable gate array processor.
We describe a page-formatted random-access holographic memory capable of storing up to 160,000 holograms. A segmented mirror array allows a 2D angle scanner to provide access to any of the stored holograms. High-speed random access can be achieved with a nonmechanical angle scanner. We demonstrate holographic storage and high-speed retrieval using an acousto- optic deflector.
We describe a page-formatted random-access holographic memory designed to store up to 160,000 holograms. The memory consists of 16 vertically spaced locations, each containing 10,000 holograms, which in turn are organized as 10 fractal-multiplexed rows of 1000 angularly-multiplexed holograms. A segmented mirror array is used to enable random access to any of the stored holograms within the access time of a non-mechanical angle scanner such as an acousto-optic deflector. Using a mechanical scanner with such a mirror array, we demonstrate storage of 10,000 holograms at a single location of the system, as well as simultaneous storage and recall of holograms at 6 locations, including the highest and lowest of the 16 locations.
We present experimental results of a page-formatted random-access holographic memory capable of storing up to 1012 bits of information. Up to 500 holograms were angularly multiplexed at each of 8 spatially multiplexed locations, using a mechanical scanner and a segmented mirror array.
A 3-D holographic optical memory is described that combines spatially and angularly multiplexed storage to yield a storage capacity of approximately 1012 bits in a crystal with volume less than 100 cm3. A non-mechanical scanning mechanism, consisting of acoustooptic deflectors and a segmented mirror, retrieves any stored hologram in a time equal to the acoustic delay through the aperture of the acoustooptic deflector
We have stored up to 5,000 holograms of high-resolution images (320 X 220 pixels) within a single crystal of Fe:LiNbO3. This storage capacity permits the construction of a processor which can compute all the inner-products between any input image and the stored images simultaneously. Without having to retrieve information from a secondary mass memory, overall computation speed of inner-products can be very high. In this paper, we will describe our architecture; address performance issues; and present experimental results on reconstruction of holograms and inner-product computation.