Superparallel holographic correlator for ultrafast database searches

Abstract

We describe a superparallel holographic optical correlator that performs two-dimensional spatial and angular multiplexing simultaneously. The key step in this architecture is the use of a holographic multiplexer to split a query image into many copies before it applies them to the holographic database. A holographic demultiplexer, in conjunction with an aperture, is used to identify the location and the angle of the brightest correlation peak. This architecture uses only O͑ p N͒ detector elements to search through N unsorted images in a single query. We demonstrate the basic features of this architecture, using three spatial locations with eight angle-multiplexed images in each location.

Double-Λmicroscopic model for entangled light generation by four-wave mixing

“…Indeed, the first experimental demonstration of squeezed light was made using FWM in a sodium atomic beam almost 25 years ago [2]. More recently, FWM in three-level Λ systems was predicted to generate squeezing by using a counter-propagating geometry [3][4][5][6]. In addition Electromagnetically Induced Transparency (EIT) in double-Λ atomic systems adds flexibility to the control of the FWM process, leading to large parametric gain and oscillations [7,8].…”

Shared-hardware alternating operation of a superparallel holographic optical correlator and a superparallel holographic RAM

“…(12). In order to increase the dimensionality of the system, it is necessary to record an HMU with multiplexing in increased spatial-and angular-dimensions.…”

“…The angular coordinate for the image is sent to a beam deflector (e.g., a pair of acousto -optic deflectors), which orients the read beam at the desired angle, which in turn is translated to a specific position by the redirector. A combination of the reducing telescope, holographic multiplexer, redirector, and the lenslet array produces a copy of the read beam simultaneously at each of the locations (12) on the HMU. The image stored at this angle would be recalled from each spatial location.…”

“…Recently, we demonstrated a super-parallel holographic optical correlator (SPHOC) (12) , which uniquely identifies N images from a database using only 2 N number of detector elements. Briefly, in this system, the spatial location and the reference beam angle for the matched image are identified by using a spatio-angular decoupling architecture, consisting of a combination of a lenslet array, a holographic redirector, a demultiplexer, and two CCD arrays.…”

Super-parallel holographic correlator with optical fixing

“…Shahriar [5] developed a super-parallel holographic correlator by use of a holographic multiplexer-demultiplexer. This is a sophisticated system and requires the use of a high-power laser.…”