Simulating the efficacy of the implicit-electric-field-conjugation algorithm for the Roman Coronagraph with noise

Kian Milani, Ewan Douglas, Sebastiaan Haffert, Kyle Van Gorkom

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

1 Scopus citations


The Roman Coronagraph is expected to perform its high-order wavefront sensing and control (HOWFSC) with a ground-in-the-loop scheme due to the computational complexity of the Electric-Field-Conjugation (EFC) algorithm. This scheme provides the flexibility to alter the HOWFSC algorithm for given science objectives. A new alternative implicit-EFC algorithm is of particular interest as it requires no optical model to create a dark-hole, making the final contrast independent of the model accuracy. The intended HOWFSC scheme involves running EFC while observing a bright star such as ζ Puppis to create the initial dark-hole, then slew to the science target while maintaining the contrast with low-order WFSC over the given observation. Given a similar scheme, the efficacy of iEFC is simulated for two coronagraph modes, namely the Hybrid Lyot Coronagraph (HLC) and the wide-field-of-view Shaped-Pupil-Coronagraph (SPC-WFOV). End-to-end physical optics models for each mode serve as the tool for the simulations. Initial monochromatic simulations are presented and compared with monochromatic EFC results obtained with the FALCO software. Various sets of calibration modes are tested to understand the optimal modes to use when generating an iEFC response matrix. Further iEFC simulations are performed using broadband images with the assumption that ζ Puppis is the stellar object being observed. Shot noise, read noise, and dark current are included in the broadband simulations to determine if iEFC could be a suitable alternative to EFC for the Roman Coronagraph.

Original languageEnglish (US)
Title of host publicationTechniques and Instrumentation for Detection of Exoplanets XI
EditorsGarreth J. Ruane
ISBN (Electronic)9781510665743
StatePublished - 2023
EventTechniques and Instrumentation for Detection of Exoplanets XI 2023 - San Diego, United States
Duration: Aug 21 2023Aug 24 2023

Publication series

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


ConferenceTechniques and Instrumentation for Detection of Exoplanets XI 2023
Country/TerritoryUnited States
CitySan Diego


  • contrast
  • coronagraph
  • dark-hole
  • deformable mirrors

ASJC Scopus subject areas

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


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