Two dimensional transform generator

Details Two dimensional transform generator Two dimensional transform generator

1998-11-05

2002-07-16

Epps, Georgia (Department: 2873)

Optical: systems and elements

Optical modulator

Light wave temporal modulation

C359S257000, C359S237000, C359S249000

Reexamination Certificate

active

06421163

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed to a system for performing a two dimensional transform, such as a two dimensional Fourier transform and, more particularly, to a system that performs the transformation in parallel.
2. Description of the Related Art
Many problems in computer science, particularly image processing problems, require the processing of vary large amounts of data. For example, the Fourier transform of a two dimensional image to allow the edges of objects in the image to be located is a computationally intensive operation generally performed on special array processing computers. The transform takes a considerable amount of time to perform and the computers are very expensive. What is needed is a system that performs a two dimensional transform by performing the operations in parallel to reduce the time required. What is also needed is a system that is low in cost.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a system that performs a two dimensional transform very quickly by performing steps of the transform in parallel.
It is an additional object of the present invention to provide a system that can be created at lower cost than array processors.
It is also an object of the present invention to provide an optical processing device to perform a two dimensional transform.
The above objects can be attained by a system that optically performs complex transforms such as Fourier transforms. The system includes a pixel addressable spatial modulator that adjusts the phase of the light of each pixel. A transform lens, such as a Fourier lens, performs a two dimensional transform of the pixels' outputs. The transformed outputs are sampled by a light detector and processed by a computer into the final transform.
The invention is an arrangement of optical and electronic devices, said arrangement capable of constructing and summing a finite series transformation of one function in terms of other functions.
These together with other objects and advantages which will be subsequently apparent, reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout.
In the basic configuration of the invention an amplitude beamsplitter divides an incoming beam into two usually equal portions. One portion enters the k
0
circuit, the other enters the k
m,n
circuit. The beam of the k
m,n
circuit passes to a spatial light phase modulator designated SLM, where it is further spatially divided into a multiplicity of pixel beams. The spatial light modulator, SLM, controls the relative phase of these pixel beams which are all simultaneously directed to form an interference pattern on a surface. Aside from the temporal oscillation at optical frequencies, the amplitude of the electric and magnetic field as a function of the x and y coordinates along this surface is a portion of the sought-after sum of the series eigenfunction expansion of a function F(x, y).
The invention provides that an optical detector array may collect the pattern for further analysis and adaptation for viewing. The invention further directs the beam of the k
0
circuit to said surface with such amplitude and phase as to add a bias field to the interference pattern. This bias field allows the use of square law detectors at said surface which otherwise cannot record the relative sign or phase of the field amplitudes within the pattern.
The invention provides methods by which all the portions may be produced separately on the surface and then added in a digital interface computer to produce F(x, y).
The invention is anticipated in particular for generating and summing Fourier eigenfunctions. However, adaptations within the invention provide the generation and summation of other functions as well.


REFERENCES:
patent: 4376950 (1983-03-01), Brown et al.
patent: 4566031 (1986-01-01), Kirk
patent: 4813761 (1989-03-01), Davis et al.
patent: 5029220 (1991-07-01), Juday
patent: 5036512 (1991-07-01), Cloonan
patent: 5040140 (1991-08-01), Horner
patent: 5079555 (1992-01-01), Turpin
patent: 5107351 (1992-04-01), Leib
patent: 5258860 (1993-11-01), Schehrer et al.
patent: 5276636 (1994-01-01), Cohn
patent: 5381249 (1995-01-01), Burney
patent: 5384573 (1995-01-01), Turpin
patent: 5416618 (1995-05-01), Juday
patent: 5523881 (1996-06-01), Florence et al.
patent: 5548418 (1996-08-01), Gaynor et al.
patent: 5600383 (1997-02-01), Hornbeck
patent: 5736958 (1998-04-01), Turpin
patent: 5751243 (1998-05-01), Turpin
patent: 5767993 (1998-06-01), Burney
patent: 5859728 (1999-01-01), Colin et al.
patent: 6055086 (2000-04-01), Soutar et al.
Henry Stark, Academic Press,Applications of Optical Fourier Transforms, 1982, pp. 6-10.
Joseph W. Goodman, The McGraw Hill Co., Inc.,Introduction to Fourier Optics, (revised) 1996, pp. 237-242.
Dorothy Garbose Crane, Library of Congress,Crystal Lattices, 1976, pp. 64-66.
Joseph L. Horner, Academic Press,Optical Signal Processing, 1987, pp. 31-35.
Louis C. Phillips et al., Proc. SPIE, Moving target SAR/SAR Imaging Using the ImSyn™ Processor, 1996, vol. 2751, pp. 1-11.
Terry M. Turpin, IEEE, Spectrum Analysis Using Optical Processing, 1981, vol. 69, No. 1, pp. 79-92.
William R. Franklin, Opt. Eng.,Optical Signal Processing at Essex Corporation, 1996, vol. 35, No. 2, pp. 401-413.
A. Vander Lugt, IEEE, Signal Detection By Complex Spatial Filtering, 1963, pp. 139-145.
Haldun M. Ozaktas, Applied Optics, Digital Fourier Optics, 1996, Abstract.
Robert T. Weverka et al., Applied Optics, Photorefractive Processing for Large Adaptive Phased Arrays, 1996, Abstract.
Luis M. Bernardo et al., Applied Optics, Optical Fractional Fourier Transforms With Complex Orders, 1996, Abstract.
David Medlovic et al., Applied Optics, Optical Illustration of a Varied Fractional Fourier-Transform Order and the Radon-Wigner Display, 1996, Abstract.
Zeev Zalevsky et al., Applied Optics, Fractional Wiener Filter, 1996, Abstract.
Shlomo Greenberg et al., Applied Optics, Neural-Network Classifiers for Automatic Real-World Aerial Image Recognition, 1996, Abstract.
M. Barge et al., Applied Optics, 64-Channel Correlator Implementing a Kohonen-Like Neural Network for Handwritten-Digit Recognition, 1996, Abstract.
Sergio Granieri et al., Applied Optics, Space-Variant Optical Correlator Based on the Fractional Fourier Transform: Implementation by the Use of a Photorefractive Bi₁₂GeO (BGO) Holographic Filter, 1996, Abstract.
Jian-Gho Zhang, Applied Optics, Strict Optical Orthogonal Codes for Purely Asynchronous Code-Division Multiple-Access Applications, 1996, Abstract.
Shutian Liu et al., Applied Optics, Image-Scaling Problem in the Optical Fractional Fourier Transform, 1997, Abstract.
John H. Reif et al., Applied Optics, Efficient Parallel Algorithms for Optical Computing With the Discrete Fourier Transform (DFT) Primitive, 1997, Abstract.
Marion O. Hagler, Applied Optics, Nyquist Stability Conditions for Laser Feedback Amplifiers With Gaussian or Lorentzian Gain Profiles, 1986, Abstract.
Henry Stark et al., Applied Optics, Design of Phase Gratings by Generalized Projections, 1991, Abstract.
Rick L. Morrison, Applied Optics, Symmetries That Simplify The Design of Spot Array Phase Gratings, 1992, Abstract.
YunJe Oh et al., Applied Optics, Soliton-Repulsion Logic Gate, 1996, Abstract.
X. D. Cao et al., Applied Optics, Experimental Cascaded Operation of Low-Birefringence Nonlinear-Optical Loop Mirrors, 1996, Abstract.
Mark A. Neifeld et al., Applied Optics, Parallel Data Detection In Page-Oriented Optical Memory, 1996, Abstract.
Joby Joseph et al., Applied Optics, Optical Fourier Processing Using Photoinduced Dichronism In A Bacteriohodopsin Film, 1996, Abstract.

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