1. 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.

2. We propose to by-pass electronic recalling by using the SPHRAM-JTC architecture
SHUTTER S2
SHUTTER S1
DYNAMIC HOLOGRAM
CORRELATION BEAM
FILTER IMAGE
INPUT IMAGE
FT LENS
TARGET ID: 7968
REDIRECTOR
IMAGING
CCD
RETRIEVED
IMAGE
FLATTENING
BEAM
EXPANDER
APERTURE
DEFLECTOR
SHUTTER ARRAY
HOLOGRAPHIC
MUX/ DEMUX
MEMORY UNIT
REDUCING
TELESCOPE
READ LASER
TARGET ID:
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, (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, (2004)

3. Translation-invariant VanderLugt-type correlation of images stored via angle-multiplexing in Memplex® material
CCD
Fourier-
Transforming
Lens
Read Beam
Thin Holographic
DC-suppressed
filter
Image reconstructed from the filter
Memplex®
Holographic
Memory Unit
Recorded trace
Images Stored in the HMU
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.

4. 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

5. 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, (2001)

6. 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
Lens f Dq
HMU
Focal Plane
Prism -
Coupled
Prism-coupled LLA – single element
Prism-coupled lenslet array
 Needs to be fabricated lithographically
(a)
(b)
(c)
(d)
(e)
(f)
Focusing Part
Phase Correction Part
Lateral Direction
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