Accession Number : AD0777451

Title :   A Digital Technique of Wavefront Reconstruction at Suboptical Frequency from a Linear Sampling of the Diffraction Pattern.

Descriptive Note : Master's thesis,

Corporate Author : ILLINOIS UNIV URBANA COORDINATED SCIENCE LAB

Personal Author(s) : Lam,Peter Chi-Chung

Report Date : SEP 1973

Pagination or Media Count : 58

Abstract : An approximate but efficient method is developed for reconstructing an aperature distribution from its diffracted field recorded suboptical frequency. This method has potential application in acoustic or microwave holography. In this investigation, an attempt is made to reconstruct an aperture from its diffracted field which is recorded by a one-dimensional array of detectors located either on the x-axis or on the y-axis. From the reconstructed image, the approximate size and location of the aperture are determined. The paper comprises five chapters. Section 1.2 will briefly describe the Abbe-Porter experiments that give rise to the technique. The second chapter covers the analytic implication of such a technique. The third chapter describes the digital simulation and the pattern-recognizing process used to distinguish the reconstructed patterns of different apertures. The fourth chapter presents results obtained using simple apertures as the objects (rectangular, semicircular, and triangular apertures). Finally, concluding remarks are made in the fifth chapter.

Descriptors :   *HOLOGRAPHY, *DIGITAL SIMULATION, DIFFRACTION, PATTERNS, OPTICAL ANALYSIS, IMAGES, FOURIER TRANSFORMATION, THESES

Subject Categories : Holography

Distribution Statement : APPROVED FOR PUBLIC RELEASE