Frank Caimi

Applications of the Priz light modulator

The Priz light modulator suppresses input data at zero spatial frequency, can provide directional spatial filtering, and can perform dynamic image selection or change detection. In this paper, we summarize the Prizs performance and provide experimental confirmation of the above three image processing applications of this device.

Test and evaluation of the Soviet Prom and Priz spatial light modulators.

Five Soviet bismuth silicon oxide Prom and Priz spatial light modulators were recently tested in the United States. In this program, their performance was quantified and compared with that of the U.S. Prom. The resultant laboratory data show that the Soviet Prom is comparable with the U.S. device and that the Soviet Priz has over ten times the diffraction efficiency and over ten times more usable resolution than the Prom. Theoretical models of the dependence of diffraction efficiency on spatial frequency were also verified by experiments performed on these devices.

Photodichroic recording and storage material.

Three techniques for recording information on NaF are reviewed. H-D exposure curves for several samples are used to record, store, and reconstruct imagery.

Optical inverse radon transform

Abstract Mathematical formulation of an optical processesor that implements the inverse radon transform is described. This operation is of use in X-ray computed tomography, transaxial scanning and other image construction systems. The optical system outlined uses the convolution of two two-dimensional functions to achieve the inverse radon transform by a new implementation method.

Laser diode lensless MSF-HOE correlator.

Description of an optical pattern recognition system employing a laser-diode lensless MSF correlator based on the use of holographic optical elements (HOE). The system has size, cost, and weight advantages over conventional optical processors, and it is believed to be the first unification of MSF correlation, laser diode, and HOE technologies.

Hurter‐Driffield exposure characteristics of oriented M centers in NaF

The dichroism of the M and MA color centers in NaF is used for data storage. Optical‐density–vs–exposure (Hurter‐Driffield) curves are obtained for eight NaF samples with different impurity content and doping. Lithium‐doped NaF samples are found to exhibit a larger dichroism and a better sensitivity and fatigue resistance than other NaF samples.

Photodichroic crystals for coherent optical data processing

Abstract The use of photodichroic alkali halide crystals as re-usable input, storage, and filter plane elements in a coherent optical computer are reviewed. Various recording methods and applications are presented with emphasis on the use of the M and MA centres in NaF at room temperature.

Optical Word Recognition: Case Study In Coherent Optical Pattern Recognition

A coherent optical pattern recognition system using a frequency plane correlator with weighted matched spatial filter synthesis is described. The case study chosen to describe this application of holography is the determination of all pages in a microfilm data base on which a given key word is present.

Implementation of the inverse radon transform by optical convolution

Abstract The implementation of the inverse radon transformed by optical correlation is described. This method described does not require formation of the derivative of the projections and allows the use of a fixed mask that is both real and positive and is dependent only on the geometry of the recording system. Experimental confirmation of the concept is included.

The Photodichroic Alkali-Halides As Optical Processing Elements

The photodichroic optical recording properties of FA, M, and MA type defects and alkali-halide materials are reviewed and new advances are reported. Particular emphasis is placed on the application of crystalline KC1, NaF, and KF to a variety of optical data processing tasks including real-time spectral analysis.