Modeling non-scalar diffraction in the Princeton starshade testbed

Anthony Harness, Jeremy Kasdin, Stuart Shaklan, Philip Dumont, K. Balasubramanian

Research output: Chapter in Book/Report/Conference proceedingConference contribution

4 Scopus citations


Starshades provide a leading technology to enable the direct detection and spectroscopic characterization of Earth-like exoplanets. Two key aspects to advancing starshade technology are the demonstration of starlight suppression at science-enabling levels and validation of optical models at this high level of suppression. These technologies are addressed in current efforts underway at the Princeton Starshade Testbed. Recent experimental data suggest we are observing the effects of vector (non-scalar) diffraction, which are limiting the starshade's performance and preventing the scalar optical models from agreeing with experimental results at the deepest levels of suppression. This report outlines a model developed to simulate vector diffraction in the testbed using a full solution to Maxwell's equations propagating through narrow features of the starshade. We find that experimental results can be explained by vector diffraction as light traverses the thickness of the starshade mask and that our model is in rough agreement with observations. We provide simulation results of a number of starshade geometries as a first attempt to understand the relation of these effects to properties of the starshade masks. Finally, we outline a number of possible solutions aimed to minimize vector effects and to allow us to reach our milestone of 10-9 suppression.

Original languageEnglish (US)
Title of host publicationSpace Telescopes and Instrumentation 2018
Subtitle of host publicationOptical, Infrared, and Millimeter Wave
EditorsGiovanni G. Fazio, Howard A. MacEwen, Makenzie Lystrup
ISBN (Print)9781510619494
StatePublished - 2018
EventSpace Telescopes and Instrumentation 2018: Optical, Infrared, and Millimeter Wave - Austin, United States
Duration: Jun 10 2018Jun 15 2018

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


OtherSpace Telescopes and Instrumentation 2018: Optical, Infrared, and Millimeter Wave
Country/TerritoryUnited States

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


  • High Contrast Imaging
  • Optical Modeling
  • Starshade
  • Vector Diffraction


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