Abstract/Details

HOLOGRAPHIC RECIPROCITY LAW FAILURE, WITH APPLICATIONS TO THE THREE-DIMENSIONAL DISPLAY OF MEDICAL DATA (MULTIPLE-EXPOSURE, LATENT IMAGE, COMPUTERIZED TOMOGRAPHY)

JOHNSON, KRISTINA MARY. 
 Stanford University ProQuest Dissertations Publishing,  1984. 8408301.

Abstract (summary)

In 1973 the computerized tomography (CT) scanner revolutionized medical imaging. This machine can isolate and display in two-dimensional cross-sections, internal lesions and organs previously impossible to visualize. The possibility of three-dimensional imaging however is not yet exploited by present tomographic systems.

Using multiple-exposure holography, three-dimensional displays can be synthesizing from two-dimensional CT cross-sections.

A multiple-exposure hologram is an incoherent superposition of many individual holograms. Intuitively it is expected that holograms recorded with equal energy will reconstruct images with equal brightness. It is found however, that holograms recorded first are brighter than holograms recorded later in the superposition. This phenomena is called Holographic Reciprocity Law Failure (HRLF).

Computer simulations of latent image formation in multiple-exposure holography are one of the methods used to investigate HRLF. These simulations indicate that it is the time between individual exposures in the multiple-exposure hologram that is responsible for HRLF. This physical parameter introduces an asymmetry into the latent image formation process that favors the signal of previously recorded holograms over holograms recorded later in the superposition. The origin of this asymmetry lies in the dynamics of latent image formation, and in particular in the decay of single-atom latent image specks, which have lifetimes that are short compared to typical times between exposures.

An analytical model is developed for a double exposure hologram that predicts a decrease in the brightness of the second exposure as compared to the first exposure as the time between exposures increases. These results are consistent with the computer simulations.

Experiments investigating the influence of this parameter on the diffraction efficiency of reconstructed images in a double exposure hologram are also found to be consistent with the computer simulations and analytical results.

From this information, two techniques are presented that correct for HRLF, and succeed in reconstructing multiple holographic images of CT cross-sections with equal brightness.

The multiple multiple-exposure hologram is a new hologram that increases the number of equally bright images that can be superimposed on one photographic plate.

Indexing (details)


Subject
Optics
Classification
0752: Optics
Identifier / keyword
Pure sciences
Title
HOLOGRAPHIC RECIPROCITY LAW FAILURE, WITH APPLICATIONS TO THE THREE-DIMENSIONAL DISPLAY OF MEDICAL DATA (MULTIPLE-EXPOSURE, LATENT IMAGE, COMPUTERIZED TOMOGRAPHY)
Author
JOHNSON, KRISTINA MARY
Number of pages
190
Degree date
1984
School code
0212
Source
DAI-B 45/01, Dissertation Abstracts International
Place of publication
Ann Arbor
Country of publication
United States
ISBN
979-8-205-74505-5
University/institution
Stanford University
University location
United States -- California
Degree
Ph.D.
Source type
Dissertation or Thesis
Language
English
Document type
Dissertation/Thesis
Dissertation/thesis number
8408301
ProQuest document ID
303332163
Copyright
Database copyright ProQuest LLC; ProQuest does not claim copyright in the individual underlying works.
Document URL
https://www.proquest.com/docview/303332163/