Date of Award

3-24-2016

Document Type

Thesis

Degree Name

Master of Science

Department

Department of Engineering Physics

First Advisor

Anthony L. Franz, PhD.

Abstract

A photon sieve is a lightweight, diffractive optic which is well-suited to be a deployable primary for a space telescope. Point spread functions (PSFs) can be altered by shaping and apodizing an aperture, and a PSF that drops rapidly from the peak is desirable for high-contrast imaging. For this reason, square apodized photon sieves were simulated, designed, and tested for high-contrast performance and use in an exoplanet imaging telescope. These sieves were shown to outperform conventional optics and unapodized sieves for high-contrast imaging in a number of tests. New methods were developed for apodizing sieves, measuring PSFs, and characterizing high-contrast performance. Tests indicated that square apodized sieves could detect exoplanets with irradiance below 10-3.69 of the star's PSF peak within ten diffraction limits of separation. This was not sufficient for directly imaging earth-like exoplanets, but will be useful for other high-contrast applications. The Fresnel diffraction simulation conducted for the sieves was shown to agree closely with the experimental results. The ability to accurately apply apodizations and conduct simulations for photon sieves, measure PSFs across an extreme dynamic range, and conduct high-contrast imaging performance analyses will drive new PSF design and be useful for future high-contrast imaging work.

AFIT Designator

AFIT-ENP-MS-16-M-065

DTIC Accession Number

AD1054490

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