A high-contrast coronagraph for the MMT using phase apodization

Design and observations at 5 microns and 2 λ/D radius

J. L. Codona, M. A. Kenworthy, Philip M Hinz, J Roger P Angel, N. J. Woolf

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

30 Citations (Scopus)

Abstract

We report on the first implementation of phase apodization for high-contrast imaging at close inner working angle. It is designed for use in the 5 μm M band with the adaptive optics system at the MMT, which uses a deformable secondary for low thermal background and achieves a Strehl ratio of 90% at 5 μm. The method uses a diamond-turned ZnSe phase plate located at a cold pupil stop to diffract starlight into an "anti-halo" which suppresses the Airy diffraction pattern over a semi-circular region around the star. The design was optimized for strong suppression from the first bright Airy ring out to the control radius achievable with the MMT deformable secondary, about 9λ/D. The time-averaged PSF of a bright star agrees well with the design profile, the core with FWHM of 0.18 arcsec showing the diffraction-limited resolution of the full aperture. At 0.34 arcsec radius (2λ/D) the floor level is 3.5 × 10 -3 of the central peak, limited by residual atmospheric errors with 3 m wavelength across the aperture. The measured fluctuations at this radius averaged over 20 seconds are 2.5 × 10 -4 rms (9 magnitudes down from the peak). With the addition of active feedback to control residual speckles caused by static wavefront errors and with longer exposures, we project that exoplanet searches should reach 5σ sensitivity level > 10 magnitudes in an hour of integration.

Original languageEnglish (US)
Title of host publicationProceedings of SPIE - The International Society for Optical Engineering
Volume6269 I
DOIs
StatePublished - 2006
EventGround-based and Airborne Instrumentation for Astronomy - Orlando, FL, United States
Duration: May 25 2006May 29 2006

Other

OtherGround-based and Airborne Instrumentation for Astronomy
CountryUnited States
CityOrlando, FL
Period5/25/065/29/06

Fingerprint

apodization
coronagraphs
Stars
radii
Adaptive optics
Wavefronts
Speckle
Full width at half maximum
apertures
Diffraction patterns
stars
Diamonds
Diffraction
extrasolar planets
pupils
Feedback
adaptive optics
Imaging techniques
Wavelength
halos

Keywords

  • Extrasolar Planets
  • Phase Apodization
  • Phase Masks
  • Stellar Coronagraphs

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Condensed Matter Physics

Cite this

Codona, J. L., Kenworthy, M. A., Hinz, P. M., Angel, J. R. P., & Woolf, N. J. (2006). A high-contrast coronagraph for the MMT using phase apodization: Design and observations at 5 microns and 2 λ/D radius. In Proceedings of SPIE - The International Society for Optical Engineering (Vol. 6269 I). [62691N] https://doi.org/10.1117/12.672727

A high-contrast coronagraph for the MMT using phase apodization : Design and observations at 5 microns and 2 λ/D radius. / Codona, J. L.; Kenworthy, M. A.; Hinz, Philip M; Angel, J Roger P; Woolf, N. J.

Proceedings of SPIE - The International Society for Optical Engineering. Vol. 6269 I 2006. 62691N.

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

Codona, JL, Kenworthy, MA, Hinz, PM, Angel, JRP & Woolf, NJ 2006, A high-contrast coronagraph for the MMT using phase apodization: Design and observations at 5 microns and 2 λ/D radius. in Proceedings of SPIE - The International Society for Optical Engineering. vol. 6269 I, 62691N, Ground-based and Airborne Instrumentation for Astronomy, Orlando, FL, United States, 5/25/06. https://doi.org/10.1117/12.672727
Codona JL, Kenworthy MA, Hinz PM, Angel JRP, Woolf NJ. A high-contrast coronagraph for the MMT using phase apodization: Design and observations at 5 microns and 2 λ/D radius. In Proceedings of SPIE - The International Society for Optical Engineering. Vol. 6269 I. 2006. 62691N https://doi.org/10.1117/12.672727
Codona, J. L. ; Kenworthy, M. A. ; Hinz, Philip M ; Angel, J Roger P ; Woolf, N. J. / A high-contrast coronagraph for the MMT using phase apodization : Design and observations at 5 microns and 2 λ/D radius. Proceedings of SPIE - The International Society for Optical Engineering. Vol. 6269 I 2006.
@inproceedings{e373030209174f9d8b341f5fc20f4cd1,
title = "A high-contrast coronagraph for the MMT using phase apodization: Design and observations at 5 microns and 2 λ/D radius",
abstract = "We report on the first implementation of phase apodization for high-contrast imaging at close inner working angle. It is designed for use in the 5 μm M band with the adaptive optics system at the MMT, which uses a deformable secondary for low thermal background and achieves a Strehl ratio of 90{\%} at 5 μm. The method uses a diamond-turned ZnSe phase plate located at a cold pupil stop to diffract starlight into an {"}anti-halo{"} which suppresses the Airy diffraction pattern over a semi-circular region around the star. The design was optimized for strong suppression from the first bright Airy ring out to the control radius achievable with the MMT deformable secondary, about 9λ/D. The time-averaged PSF of a bright star agrees well with the design profile, the core with FWHM of 0.18 arcsec showing the diffraction-limited resolution of the full aperture. At 0.34 arcsec radius (2λ/D) the floor level is 3.5 × 10 -3 of the central peak, limited by residual atmospheric errors with 3 m wavelength across the aperture. The measured fluctuations at this radius averaged over 20 seconds are 2.5 × 10 -4 rms (9 magnitudes down from the peak). With the addition of active feedback to control residual speckles caused by static wavefront errors and with longer exposures, we project that exoplanet searches should reach 5σ sensitivity level > 10 magnitudes in an hour of integration.",
keywords = "Extrasolar Planets, Phase Apodization, Phase Masks, Stellar Coronagraphs",
author = "Codona, {J. L.} and Kenworthy, {M. A.} and Hinz, {Philip M} and Angel, {J Roger P} and Woolf, {N. J.}",
year = "2006",
doi = "10.1117/12.672727",
language = "English (US)",
isbn = "0819463345",
volume = "6269 I",
booktitle = "Proceedings of SPIE - The International Society for Optical Engineering",

}

TY - GEN

T1 - A high-contrast coronagraph for the MMT using phase apodization

T2 - Design and observations at 5 microns and 2 λ/D radius

AU - Codona, J. L.

AU - Kenworthy, M. A.

AU - Hinz, Philip M

AU - Angel, J Roger P

AU - Woolf, N. J.

PY - 2006

Y1 - 2006

N2 - We report on the first implementation of phase apodization for high-contrast imaging at close inner working angle. It is designed for use in the 5 μm M band with the adaptive optics system at the MMT, which uses a deformable secondary for low thermal background and achieves a Strehl ratio of 90% at 5 μm. The method uses a diamond-turned ZnSe phase plate located at a cold pupil stop to diffract starlight into an "anti-halo" which suppresses the Airy diffraction pattern over a semi-circular region around the star. The design was optimized for strong suppression from the first bright Airy ring out to the control radius achievable with the MMT deformable secondary, about 9λ/D. The time-averaged PSF of a bright star agrees well with the design profile, the core with FWHM of 0.18 arcsec showing the diffraction-limited resolution of the full aperture. At 0.34 arcsec radius (2λ/D) the floor level is 3.5 × 10 -3 of the central peak, limited by residual atmospheric errors with 3 m wavelength across the aperture. The measured fluctuations at this radius averaged over 20 seconds are 2.5 × 10 -4 rms (9 magnitudes down from the peak). With the addition of active feedback to control residual speckles caused by static wavefront errors and with longer exposures, we project that exoplanet searches should reach 5σ sensitivity level > 10 magnitudes in an hour of integration.

AB - We report on the first implementation of phase apodization for high-contrast imaging at close inner working angle. It is designed for use in the 5 μm M band with the adaptive optics system at the MMT, which uses a deformable secondary for low thermal background and achieves a Strehl ratio of 90% at 5 μm. The method uses a diamond-turned ZnSe phase plate located at a cold pupil stop to diffract starlight into an "anti-halo" which suppresses the Airy diffraction pattern over a semi-circular region around the star. The design was optimized for strong suppression from the first bright Airy ring out to the control radius achievable with the MMT deformable secondary, about 9λ/D. The time-averaged PSF of a bright star agrees well with the design profile, the core with FWHM of 0.18 arcsec showing the diffraction-limited resolution of the full aperture. At 0.34 arcsec radius (2λ/D) the floor level is 3.5 × 10 -3 of the central peak, limited by residual atmospheric errors with 3 m wavelength across the aperture. The measured fluctuations at this radius averaged over 20 seconds are 2.5 × 10 -4 rms (9 magnitudes down from the peak). With the addition of active feedback to control residual speckles caused by static wavefront errors and with longer exposures, we project that exoplanet searches should reach 5σ sensitivity level > 10 magnitudes in an hour of integration.

KW - Extrasolar Planets

KW - Phase Apodization

KW - Phase Masks

KW - Stellar Coronagraphs

UR - http://www.scopus.com/inward/record.url?scp=33749010462&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33749010462&partnerID=8YFLogxK

U2 - 10.1117/12.672727

DO - 10.1117/12.672727

M3 - Conference contribution

SN - 0819463345

SN - 9780819463340

VL - 6269 I

BT - Proceedings of SPIE - The International Society for Optical Engineering

ER -