Electronic Theses and Dissertations

Identifier

2574

Date

2016

Document Type

Thesis

Degree Name

Master of Science

Major

Electrical and Computer Engr

Concentration

Electrical Engineering

Committee Chair

Eddie Jacobs

Committee Member

Aaron Robinson

Committee Member

Sharon King

Abstract

The ability to measure the modulation transfer function (MTF) of optical systems and components was a crucial advancement in optical engineering community. This measurement has been attainable in multiple regions of the electromagnetic (EM) spectrum, including visible, infrared, ultraviolet, and more. Visible to midwave infrared (MWIR) wavelengths are a primary focus of this research, with the anticipation of expansion into longwave infrared (LWIR). MTF estimations of optical systems are proven achievable through several different techniques. Dr. Glenn Boreman developed a process for calculating the MTF of a given optical system through the use of random laser speckle. Although, it was through Dr. Ken Barnard's research that a process for directly finding the MTF of a given focal plane array (FPA) was established. Barnard's process is subject to certain limitations due to Fresnel approximations made with this technique. Specifically, decreasing detector pitch limits the accuracy of the MTF calculation due to approximations made about the diffraction that occurs in these ranges. In these approximations there exist assumptions about the statistical properties of laser speckle, namely the correlation of the speckle. In an attempt to resolve this issue, this paper aims to characterize random laser speckle upon the FPA using mutual coherency. By using an altered version of Young's double slit experiment operating in the MWIR region, we aim to measure mutual intensity of fringes upon the FPA, calculate visibility of these fringes, and prove the existence of a corresponding region of coherency in the point source of the random laser speckle while acknowledging that the random speckle is incoherent. We will attempt to validate our results by using a Lloyd's mirror interferometer in the visible wavelengths in hopes of lesser power losses in generating laser speckle.

Comments

Data is provided by the student.

Library Comment

Dissertation or thesis originally submitted to the local University of Memphis Electronic Theses & dissertation (ETD) Repository.

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