Super-parallel%20Holographic%20Random%20Access%20Memory%20(SPHRAM)%20with%20a%20Joint%20Transform%20Correlator%20(JTC)

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Super-parallel Holographic Random Access Memory
(SPHRAM) with a Joint Transform Correlator (JTC)
Rotationally-variant simulation of MiG-25 jet
movie
Correlation spot tracking movie
? SPHRAM/JTC is needed to quickly update filters
in real-time to compensate for scale and rotation
variance.
? Already demonstrated rotationally-invariant
translation-invariant correlation
Rotationally-invariant movie of MiG-25 jet
Experimental correlation spot tracking movie
A. Heifetz, J.T. Shen, J.K. Lee, R. Tripathi,
M.S. Shahriar, Translation-Invariant Correlation
of Images Stored via Holographic Angle-
Multiplexing in a Memplex? Volume Photopolymer
Material, submitted to Opt. Lett.
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We propose to by-pass electronic recalling by
using the SPHRAM-JTC architecture
Images stored in the Super-Parallel Holographic
RAM will be correlated in a translation-invariant
manner. We will use a joint-transform correlator
architecture based on a high speed dynamic
holographic material.
M.S. Shahriar, R. Tripathi, M. Kleinschmit, J.
Donoghue, W. Weathers, M. Huq, and J.T. Shen,
Superparallel Holographic Correlator for
Ultrafast Database Searches, Opt. Lettt. 28,
525-527 (2003)
M.S. Shahriar, R. Tripathi, M. Huq, J. Donoghue,
and J.T. Shen, Shared-Hardware Alternating
Operation of a Superparallel Holographic Optical
Correlator and Super-Parallel Holographic Random
Access Memory, Opt. Eng. 43, 1856-1861 (2004)
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Translation-invariant VanderLugt-type correlation
of images stored via angle-multiplexing in
Memplex material
We demonstrate translation invariant correlation
of images stored in a Holographic Memory Unit
(HMU) using the VanderLugt architecture. Twenty
three binary images of MiG-25 jet in different
locations in the frame are stored via
angle-multiplexing in the Memplex HMU. Scanning
the angle of the read beam retrieves the stored
images one at a time. Thin holographic filter
contains a DC-suppressed Fourier transform of the
MiG-25 jet. Correlation spot indicates the
location of the plane in the frame. Superimposing
the correlation spots produces a trajectory
trace.
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Translation-invariant correlation of images
stored via angle-multiplexing in a
thick-holographic Memplex material
We demonstrate the quality of our holographic
storage by presenting several captures of the
images retrieved from the HMU.
Sample images reconstructed from HMU
Below are the traces of the MiG-25 jet produced
when the SLM acts as the source of images and
when the HMU is the source of images are
compared.
SLM as image source trace
HMU as image source trace
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Sn2P2S6 is the fastest crystal for SPHRAM/JTC
translation-invariant correlation
Refractive indices and rotation angle of the
indicatrix
Structure of Sn2P2S6. The unit cell is indicated
by the dashed lines
? Joint transform correlation with Sn2P2S6 at
10KHz has been reported
?Technology is available in Switzerland -- needs
to be transferred to the U.S.
R. Ryf, G. Montemezzani, P. Günter, A.A. Grabar,
I.M. Stoika, and Yu. M. Vysochanskii,
High-frame-rate joint Fourier-transform
correlator based on Sn2P2S6 crystal, Opt. Lett.
26, 1666-1668 (2001)
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Prism-coupled lenslet array is a crucial
component of SPHRAM
? Must translate a spatial position in the
transverse direction to a specific angle while
maintaining the shape of the beam
Prism-coupled LLA single element
Prism-coupled lenslet array
? Needs to be fabricated lithographically
Vertical focusing and phase correction by a
multilayer structure
Lateral focusing and phase correction by
a physical surface profile
Lateral focusing plus different phase corrections