Dr. Brian D. Kern Profile

Dr. Brian D. Kern

Engineer at Jet Propulsion Lab

SPIE Involvement:

Author

Publications (84)

SPIE Journal Paper | 11 October 2023 Open Access

End-to-end numerical modeling of the Roman Space Telescope coronagraph

John Krist, John Steeves, Brandon Dube, A.J. Eldorado Riggs, Brian Kern, David Marx, Eric Cady, Hanying Zhou, Ilya Poberezhskiy, Caleb Baker, James McGuire, Bijan Nemati, Gary Kuan, Bertrand Mennesson, John Trauger, Navtej Saini, Sergi Hildebrandt Rafels

JATIS, Vol. 9, Issue 04, 045002, (October 2023) https://doi.org/10.1117/12.10.1117/1.JATIS.9.4.045002

KEYWORDS: Coronagraphy, Actuators, Space telescopes, Numerical modeling, Wavefronts, Modeling, Stars, Monochromatic aberrations, Polarization, Simulations

Read Abstract +

DOWNLOAD PAPER

Proceedings Article | 5 October 2023 Poster + Paper

Roman coronagraph HOWFSC modeling: case study and raw contrast performance prediction

Hanying Zhou, Brian Kern, Nathan Bush, John Krist, Ilya Poberezhskiy

Proceedings Volume 12680, 1268027 (2023) https://doi.org/10.1117/12.2681773

KEYWORDS: Modeling, Coronagraphy, Calibration, Data modeling, Wavefront sensors, Vacuum, Risk assessment, Optical actuators, Astronomical detectors, Nonlinear control

Read Abstract +

SPIE Journal Paper | 27 September 2023

Analytical performance model and error budget for the Roman coronagraph instrument

Bijan Nemati, John Krist, Ilya Poberezhskiy, Brian Kern

JATIS, Vol. 9, Issue 03, 034007, (September 2023) https://doi.org/10.1117/12.10.1117/1.JATIS.9.3.034007

KEYWORDS: Stars, Analytic models, Planets, Error analysis, Coronagraphy, Sensors, Performance modeling, Speckle, Signal to noise ratio, Calibration

Read Abstract +

The Nancy Grace Roman Space Telescope (“Roman”), under development by NASA, will investigate possible causes for the phenomenon of dark energy and detect and characterize extrasolar planets. The 2.4 m space telescope has two main instruments: a wide-field, infrared imager and a coronagraph. The coronagraph instrument (CGI) is a technology demonstrator designed to help bridge the gap between the current state-of-the-art space and ground instruments and future high-contrast space coronagraphs that will be capable of detecting and characterizing Earth-like planets in the habitable zones of other stars. Using adaptive optics, including two high-density deformable mirrors and low- and high-order wavefront sensing and control, CGI is designed to suppress the star light by up to nine orders of magnitude, potentially enabling the direct detection and characterization of Jupiter-class exoplanets. Contrast is the measure of starlight suppression, and high contrast is the chief virtue of a coronagraph. But it is not the only important characteristic: contrast must be balanced against acceptance of planet light. The remaining unsuppressed starlight must also have a stable morphology to allow further estimation and subtraction. To achieve all these goals in the presence of the disturbance and radiation environment of space, the coronagraph must be designed and fabricated as a highly optimized system. The CGI error budget is the top-level tool used to guide the optimization, enabling trades of various competing errors. The error budget is based on an analytical model, which enables rapid calculation and tracking of performance for the numerous and diverse questions that arise in the system engineering process. We outline the coronagraph system engineering approach and the error budget. We then describe in detail the analytical model for direct imaging and spectroscopy and show how it connects to the error budget. We introduce a number of useful ancillary metrics that provide insight into the capabilities of the instrument. Since models always need to be validated, we describe the validation approach for the CGI analytical model.

Proceedings Article | 27 August 2022 Presentation + Paper

The Roman Space Telescope coronagraph technology demonstration: current status and relevance to future missions

B. Mennesson, V. Bailey, R. Zellem, S. Hildebrandt, M. Ygouf, J. Rhodes, N. Zimmerman, B. Nemati, G. Gonzalez, E. Cady, B. Kern, T. Koch, J. Krist, K. Heydorff, T. Luchik, F. Mok, P. Morrissey, I. Poberezhskiy, A. Riggs, F. Shi, F. Zhao, R. Akeson, L. Armus, A. Greenbaum, J. Ingalls, P. Lowrance

Proceedings Volume 12180, 121801W (2022) https://doi.org/10.1117/12.2629176

KEYWORDS: Coronagraphy, Wavefront sensors, Electron multiplying charge coupled devices, Imaging spectroscopy, Wavefronts, Stars, Spectroscopy, Performance modeling, Cameras, Observatories

Read Abstract +

Proceedings Article | 27 August 2022 Presentation + Paper

Laboratory demonstration of high contrast with the PIAACMC coronagraph on an obstructed and segmented aperture

Ruslan Belikov, Dan Sirbu, David Marx, Camilo Mejia Prada, Eduardo Bendek, Eugene Pluzhnik, Stephen Bryson, Brian Kern, Olivier Guyon, Kevin Fogarty, Justin Knight, Daniel Wilson, John Hagopian

Proceedings Volume 12180, 1218025 (2022) https://doi.org/10.1117/12.2630474

KEYWORDS: Coronagraphy, Stars, Yield improvement, Telescopes, Tolerancing, Wavefronts, Speckle, Modulation, Mirrors, Exoplanets

Read Abstract +

Proceedings Article | 27 August 2022 Presentation + Paper

Initial laboratory demonstration of multi-star wavefront control at the occulting mask coronagraph testbed

Dan Sirbu, Ruslan Belikov, Eduardo Bendek, David Marx, A.J. Eldorado Riggs, Garreth Ruane, Camilo Mejia Prada, Brian Kern

Proceedings Volume 12180, 121802A (2022) https://doi.org/10.1117/12.2630639

KEYWORDS: Diffraction, Stars, Wavefronts, Coronagraphy, Photomasks, Cameras, Speckle, Manufacturing, Control systems, Imaging systems

Read Abstract +

Proceedings Article | 27 August 2022 Presentation + Paper

Roman coronagraph instrument: engineering overview and status

Ilya Poberezhskiy, Kathryn Heydorff, Thomas Luchik, Feng Zhao, Eric Cady, Gasia Bedrosian, Mark Colavita, Brandon Creager, Renaud Goullioud, Tyler Groff, Amanda Grue, Brian Monacelli, Patrick Morrissey, Joshua Kempenaar, Brian Kern, Matthew King, Timothy Koch, John Krist, Gary Kuan, Jonathan Lam, Dorothy Lewis, Fai Mok, David Muliere, Bijan Nemati, Charley Noecker, Jeffrey Oseas, A.J. Riggs, Fang Shi, Belinda Shreckengost

Proceedings Volume 12180, 121801X (2022) https://doi.org/10.1117/12.2630540

KEYWORDS: Coronagraphy, Electronics, Cameras, Interfaces, Mirrors, Control systems, Optical alignment, Observatories, Space operations, Optical benches

Read Abstract +

SPIE Journal Paper | 26 February 2022

Coronagraph design with the electric field conjugation algorithm

Jorge Llop-Sayson, A. J. Eldorado Riggs, Dimitri Mawet, Dwight Moody, Brian Kern, Erkin Sidick

JATIS, Vol. 8, Issue 01, 015003, (February 2022) https://doi.org/10.1117/12.10.1117/1.JATIS.8.1.015003

KEYWORDS: Coronagraphy, Dielectrics, Actuators, Point spread functions, Planets, Wavefronts, Metals, Optical instrument design, Optical components, Stars

Read Abstract +

Proceedings Article | 1 September 2021 Presentation + Paper

Model validation of phase-induced amplitude apodization complex mask coronagraph for LUVOIR-A in vacuum

Dan Sirbu, David Marx, Ruslan Belikov, Eduardo Bendek, Kevin Fogarty, Brian Kern, Olivier Guyon, Eugene Pluzhnyk, Daniel Wilson

Proceedings Volume 11823, 118230R (2021) https://doi.org/10.1117/12.2594901

KEYWORDS: Apodization, Coronagraphy, Mirrors, Point spread functions, Wavefronts, Manufacturing, Exoplanets, Performance modeling, Data modeling, Cameras

Read Abstract +

Proceedings Article | 1 September 2021 Presentation + Paper

Results from the laboratory demonstration of a PIAACMC coronagraph with a segmented aperture

David Marx, Ruslan Belikov, Dan Sirbu, Brian Kern, Camilo Prada, Eduardo Bendek, Daniel Wilson

Proceedings Volume 11823, 118230O (2021) https://doi.org/10.1117/12.2595066

KEYWORDS: Coronagraphy, Telescopes, Actuators, Modulation, Mirrors, Diffraction, Speckle, Photomasks, Image segmentation

Read Abstract +

Proceedings Article | 1 September 2021 Presentation + Paper

The Roman Space Telescope coronagraph technology demonstration: current status and relevance to future missions

B. Mennesson, V. P. Bailey, R. Zellem, N. Zimmerman, M. Ygouf, S. Hildebrandt, J. Rhodes, J. Kasdin, B. Macintosh, M. Turnbull, E. Douglas, A. Mandell, B. Nemati, G. Gonzalez, E. Cady, B. Kern, J. Krist, F. Shi, F. Mok, P. Morrissey, K. Heydorff, I. Pobereszhskiy, F. Zhao, T. Luchik, E. Maier, R. Akeson, L. Armus, J. Ingalls, P. Lowrance, T. Meshkat

Proceedings Volume 11823, 1182310 (2021) https://doi.org/10.1117/12.2603343

KEYWORDS: Coronagraphy, Electron multiplying charge coupled devices, Wavefront sensors, Cameras, Wavefronts, Imaging spectroscopy, Stars, Imaging systems, Spectroscopy, Polarimetry

Read Abstract +

Proceedings Article | 12 January 2021 Presentation + Paper

Roman space telescope coronagraph: engineering design and operating concept

Ilya Poberezhskiy, Thomas Luchik, Feng Zhao, Margaret Frerking, Scott Basinger, Eric Cady, M. Mark Colavita, Brandon Creager, Nanaz Fathpour, Renaud Goullioud, Tyler Groff, Patrick Morrissey, Joshua Kempenaar, Brian Kern, Timothy Koch, John Krist, Fai Mok, David Muliere, Bijan Nemati, A.J. Riggs, Byoung-Joon Seo, Fang Shi, Belinda Shreckengost, John Steeves, Hong Tang

Proceedings Volume 11443, 114431V (2021) https://doi.org/10.1117/12.2563480

KEYWORDS: Infrared telescopes, James Webb Space Telescope, Telescopes, Coronagraphy, Infrared radiation, Instrumentation engineering, Optical instrument design, Wavefronts, Imaging spectroscopy, Infrared imaging

Read Abstract +

Proceedings Article | 15 December 2020 Presentation + Paper

The Nancy Grace Roman Space Telescope Coronagraph Instrument (CGI) technology demonstration

N. Jeremy Kasdin, Vanessa Bailey, Bertrand Mennesson, Robert Zellem, Marie Ygouf, Jason Rhodes, Thomas Luchik, Feng Zhao, A. J. Eldorado Riggs, Byoung-Joon Seo, John Krist, Brian Kern, Hong Tang, Bijan Nemati, Tyler Groff, Neil Zimmerman, Bruce Macintosh, Margaret Turnbull, John Debes, Ewan Douglas, Roxana Lupu

Proceedings Volume 11443, 114431U (2020) https://doi.org/10.1117/12.2562997

KEYWORDS: Coronagraphy, Imaging spectroscopy, Planets, Infrared telescopes, James Webb Space Telescope, Imaging systems, Wavefronts, Algorithm development, Jupiter, Infrared radiation

Read Abstract +

Proceedings Article | 13 December 2020 Poster + Paper

Prediction and evaluation of the image of the WFIRST coronagraph pupil at the shaped-pupil mask

David Marx, Brian Kern, John Krist, Bala Balasubramanian, A. J. Eldorado Riggs, Byoung-Joon Seo, Eric Cady, Hong Tang, Camilo Prada, Garreth Ruane, Fang Shi, Charley Noecker, Blake Crowther

Proceedings Volume 11443, 1144339 (2020) https://doi.org/10.1117/12.2562629

KEYWORDS: Coronagraphy, Image analysis, Telescopes, Optical instrument design, Optimization (mathematics), Wavefronts, Deformable mirrors, Modulation, Tolerancing, Performance modeling

Read Abstract +

Proceedings Article | 13 December 2020 Presentation + Paper

Roman CGI testbed HOWFSC modeling and validation

Hanying Zhou, John Krist, Byoung-Joon Seo, Brian Kern, Eric Cady, Ilya Poberezhskiy

Proceedings Volume 11443, 114431W (2020) https://doi.org/10.1117/12.2561087

KEYWORDS: Coronagraphy, Wavefronts, Diffraction, Instrument modeling, Observatories, Performance modeling, Deformable mirrors

Read Abstract +

SPIE Journal Paper | 9 November 2020

Wavefront sensing and control in space-based coronagraph instruments using Zernike’s phase-contrast method

Garreth Ruane, James Kent Wallace, John Steeves, Camilo Mejia Prada, Byoung-Joon Seo, Eduardo Bendek, Carl Coker, Pin Chen, Brendan Crill, Jeff Jewell, Brian Kern, David Marx, Phillip Poon, David Redding, A. J. Eldorado Riggs, Nicholas Siegler, Robert Zimmer

JATIS, Vol. 6, Issue 04, 045005, (November 2020) https://doi.org/10.1117/12.10.1117/1.JATIS.6.4.045005

KEYWORDS: Coronagraphy, Wavefronts, Stars, Actuators, Wavefront sensors, Space telescopes, Cameras, Equipment, Wavefront errors, Wavefront aberrations

Read Abstract +

SPIE Journal Paper | 7 October 2020

Microelectromechanical deformable mirror development for high-contrast imaging, part 2: the impact of quantization errors on coronagraph image contrast

Garreth Ruane, Daniel Echeverri, Eduardo Bendek, Brian Kern, David Marx, Dimitri Mawet, Camilo Mejia Prada, A.J. Eldorado Riggs, Byoung-Joon Seo, Eugene Serabyn, Stuart Shaklan

JATIS, Vol. 6, Issue 04, 045002, (October 2020) https://doi.org/10.1117/12.10.1117/1.JATIS.6.4.045002

KEYWORDS: Quantization, Coronagraphy, Actuators, Microelectromechanical systems, Deformable mirrors, Electronics, Control systems, Wavefronts, Stars, Error analysis

Read Abstract +

Proceedings Article | 16 September 2019 Presentation + Paper

WFIRST low order wavefront sensing and control (LOWFS/C) performance on line-of-sight disturbances from multiple reaction wheels

Fang Shi, Joel Shields, Tuan Truong, Byoung-Joon Seo, Felipe Fregoso, Brian Kern, David Marx, Keith Patterson, Camilo Mejia Prada, John Shaw, Chris Shelton

Proceedings Volume 11117, 111170I (2019) https://doi.org/10.1117/12.2530486

KEYWORDS: Coronagraphy, Wavefront sensors, Wavefronts, Observatories, Wavefront distortions, Telescopes, Device simulation, Hardware testing

Read Abstract +

Proceedings Article | 16 September 2019 Presentation + Paper

Testbed demonstration of high-contrast coronagraph imaging in search for Earth-like exoplanets

Byoung-Joon Seo, Keith Patterson, Kunjithapatham Balasubramanian, Brendan Crill, Talso Chui, Daniel Echeverri, Brian Kern, David Marx, Dwight Moody, Camilo Mejia Prada, Garreth Ruane, Fang Shi, John Shaw, Nick Siegler, Hong Tang, John Trauger, Daniel Wilson, Robert Zimmer

Proceedings Volume 11117, 111171V (2019) https://doi.org/10.1117/12.2530033

KEYWORDS: Coronagraphy, Exoplanets, Space telescopes, James Webb Space Telescope, Infrared telescopes, Visible radiation, Aerospace engineering, Space operations, Telescopes, Near infrared

Read Abstract +

Proceedings Article | 16 September 2019 Presentation + Paper

Design description and commissioning performance of a stable coronagraph technology development testbed for direct imaging of Earth-like exoplanets

Keith Patterson, Byoung-Joon Seo, Kunjithapatham Balasubramanian, Talso Chui, Brendan Crill, John Gill, Brian Kern, Ray Lam, David Marx, Dwight Moody, Camilo Mejia Prada, Garreth Ruane, Jordan Rupp, John Shaw, Fang Shi, Nicholas Siegler, Hong Tang, John Trauger, Victor White, Daniel Wilson, Karl Yee, Robert Zimmer

Proceedings Volume 11117, 111171U (2019) https://doi.org/10.1117/12.2530401

KEYWORDS: Exoplanets, Coronagraphy, Deformable mirrors, Visible radiation, Turbulence, Convection, Composites, Vibration isolation, Electronics, Wavefront sensors

Read Abstract +

Proceedings Article | 9 September 2019 Presentation + Paper

Directly constraining low-order aberration sensitivities in the WFIRST coronagraph design

A.J. Eldorado Riggs, Garreth Ruane, Brian Kern

Proceedings Volume 11117, 111170F (2019) https://doi.org/10.1117/12.2529588

KEYWORDS: Coronagraphy, Exoplanets, Diffraction, Optical instrument design, Telescopes, Polarization

Read Abstract +

Proceedings Article | 9 September 2019 Presentation + Paper

WFIRST Phase B HLC occulter mask baselining and testbed WFC performance validation

Hanying Zhou, John Krist, Brian Kern, Byoung-Joon Seo, Eric Cady, Bijan Nemati, Dwight Moody, A.J. Eldorado Riggs, David Marx, Daniel Wilson, Kunjithapatham Balasubramanian, Ilya Poberezhskiy, Scott Basinger

Proceedings Volume 11117, 111170H (2019) https://doi.org/10.1117/12.2530672

KEYWORDS: Wavefronts, Tolerancing, Coronagraphy, Telescopes, Performance modeling, Control systems, Mask making, Optical instrument design, Aerospace engineering, Space operations

Read Abstract +

Proceedings Article | 22 August 2018 Presentation + Paper

Hybrid lyot coronagraph for WFIRST: high contrast testbed demonstration in flight-like low flux environment

Byoung-Joon Seo, Fang Shi, Bala Balasubramanian, Eric Cady, Brian Gordon, Brian Kern, Raymond Lam, David Marx, Dwight Moody, Richard Muller, Keith Patterson, Ilya Poberezhskiy, Camilo Mejia Prada, A.J. Eldorado Riggs, John Trauger, Daniel Wilson

Proceedings Volume 10698, 106982P (2018) https://doi.org/10.1117/12.2314358

KEYWORDS: Coronagraphy, Telescopes, Wavefronts, Space telescopes, Low light level imaging

Read Abstract +

Proceedings Article | 9 August 2018 Paper

Fast linearized coronagraph optimizer (FALCO) I: a software toolbox for rapid coronagraphic design and wavefront correction

A J Eldorado Riggs, Garreth Ruane, Erkin Sidick, Carl Coker, Brian Kern, Stuart Shaklan

Proceedings Volume 10698, 106982V (2018) https://doi.org/10.1117/12.2313812

KEYWORDS: Coronagraphy, Wavefronts, Wave propagation, Instrument modeling, MATLAB, Telescopes, Fourier transforms, Deformable mirrors, Wavefront compensation

Read Abstract +

Proceedings Article | 9 August 2018 Paper

Lessons for WFIRST CGI from ground-based high-contrast systems

Vanessa Bailey, Michael Bottom, Eric Cady, Faustine Cantalloube, Jozua de Boer, Tyler Groff, John Krist, Maxwell Millar-Blanchaer, Arthur Vigan, Jeffrey Chilcote, Elodie Choquet, Robert De Rosa, Julien Girard, Olivier Guyon, Brian Kern, Anne-Marie Lagrange, Bruce Macintosh, Jared Males, Christian Marois, Tiffany Meshkat, Julien Milli, Mamadoue N'Diaye, Henry Ngo, Eric Nielsen, Jason Rhodes, Garreth Ruane, Rob van Holstein, Jason Wang, Wenhao Xuan

Proceedings Volume 10698, 106986P (2018) https://doi.org/10.1117/12.2313820

KEYWORDS: Calibration, Stars, Point spread functions, Polarization, Coronagraphy, Satellites, Telescopes, Planets, Polarimetry, Imaging spectroscopy

Read Abstract +

Proceedings Article | 7 August 2018 Paper

Fast linearized coronagraph optimizer (FALCO) III: optimization of key coronagraph design parameters

Carl Coker, Garreth Ruane, A J Eldorado Riggs, Erkin Sidick, Byoung-Joon Seo, Brian Kern, David Marx, Stuart Shaklan

Proceedings Volume 10698, 1069851 (2018) https://doi.org/10.1117/12.2313788

KEYWORDS: Coronagraphy, Stars, Telescopes, Space telescopes, Actuators, Planets, Exoplanets, Diffraction, Optimization (mathematics), Deformable mirrors

Read Abstract +

Proceedings Article | 1 August 2018 Presentation + Paper

Design and performance analysis of a PIAACMC coronagraph on a segmented aperture

Ruslan Belikov, Stephen Bryson, Dan Sirbu, Olivier Guyon, Eduardo Bendek, Brian Kern

Proceedings Volume 10698, 106981H (2018) https://doi.org/10.1117/12.2314202

KEYWORDS: Coronagraphy, Mirrors, Apodization, Deformable mirrors, Manufacturing, Exoplanets, Near field optics, Phase shifts, Geometrical optics, Image segmentation

Read Abstract +

Proceedings Article | 30 July 2018 Presentation + Paper

WFIRST low order wavefront sensing and control dynamic testbed performance under the flight like photon flux

Fang Shi, Byoung-Joon Seo, Eric Cady, Brian Kern, Raymond Lam, David Marx, Keith Patterson, Camilo Mejia Prada, John Shaw, Chris Shelton, Joel Shields, Hong Tang, Tuan Truong

Proceedings Volume 10698, 106982O (2018) https://doi.org/10.1117/12.2312746

KEYWORDS: Sensors, Coronagraphy, Wavefronts, Cameras, Stars, Wavefront sensors, Line of sight stabilization, Mirrors, Telescopes, Actuators

Read Abstract +

To maintain the required performance for the WFIRST Coronagraph Instrument (CGI) in a realistic space environment, a Low Order Wavefront Sensing and Control (LOWFS/C) subsystem is necessary. The WFIRST CGI LOWFS/C subsystem will use the Zernike wavefront sensor, which has a phase-shifting disk combined with the coronagraph’s focal plane mask, to sense the low-order wavefront drift and line-of-sight (LoS) error using the rejected starlight. The dynamic tests on JPL’s Occulting Mask Coronagraph (OMC) Testbed have demonstrated that LOWFS/C can maintain coronagraph contrast to better than 10^-8 in presence of WFIRST-like line of sight and low order wavefront disturbances in both Shaped Pupil Coronagraph (SPC) and Hybrid Lyot Coronagraph (HLC) modes. However, the previous dynamic tests have been done using a bright source with photon flux equivalent to stellar magnitude of MV = -3.5. The LOWFS/C technology development on the OMC testbed has since then concentrated in evaluating and improving the LOWFS/C performance under the realistic photon flux that is equivalent to WFIRST Coronagraph target stars. Our recent testbed tests have demonstrated that the LOWFS/C can work cohesively with the stellar light suppression wavefront control, which brings broad band coronagraph contrast from ~1x10^-6 to 6x10^-9, while LOWF/C is simultaneously suppressing the WFIRST like LoS and low order wavefront drift disturbances on a source that photon flux is equivalent to a MV = 2 star. This lab demonstration mimics the CGI initial dark hole establish process on a bright reference star. We have also demonstrated on the testbed that LOWFS/C can maintain the coronagraph contrast by suppressing the WFIRST like line-of-sight disturbances on a fainter MV = 5 star. This mimics scenario of CGI science target observations. In this paper we will present the recent dynamic testbed performance results of LOWFS/C LoS loops and low order wavefront error correction loop on the flight like photon flux.

Proceedings Article | 16 July 2018 Presentation + Paper

Shaped pupil coronagraph: disk science mask experimental verification and testing

David Marx, Eric Cady, A. J. Eldorado Riggs, Camilo Prada, Brian Kern, Byoung-Joon Seo, Fang Shi

Proceedings Volume 10698, 106981E (2018) https://doi.org/10.1117/12.2312602

KEYWORDS: Coronagraphy, Spatial frequencies, Speckle, Performance modeling, Wavefronts, Fourier transforms, Mirrors, Deformable mirrors

Read Abstract +

Proceedings Article | 16 July 2018 Presentation + Paper

WFIRST coronagraph flight performance modeling

John Krist, Robert Effinger, Brian Kern, Milan Mandic, James McGuire, Dwight Moody, Patrick Morrissey, Ilya Poberezhskiy, A. J. Riggs, Navtej Saini, Erkin Sidick, Hong Tang, John Trauger

Proceedings Volume 10698, 106982K (2018) https://doi.org/10.1117/12.2310043

KEYWORDS: Coronagraphy, Thermal modeling

Read Abstract +

Proceedings Article | 10 July 2018 Presentation

The wide field infrared survey telescope (WFIRST) observatory: design formulation (phase-A) overview (Conference Presentation)

Thomas Casey, Nerses Armani, Wes Alexander, Lisa Bartusek, Carl Blaurock, David Braun, Alexander Carra, David Content, Yves Conturie, Christine Cottingham, Richard Demers, Michael Dipirro, Robert Effinger, Robert Egerman, Frank Forkl, Guangjun Gao, John Gygax, John Hagopian, Timothy Hahm, John Hawk, Gurnie Hobbs, Clifton Jackson, Alden Jurling, Brian Kern, Jeffrey Kruk, Xiaoyi Li, Kuo-chia Liu, Catherine Marx, Marzouk Marzouk, Carson McDonald, Seke Godo, Mark Melton, James Mondello, M. Charley Noecker, Bert Pasquale, Hume Peabody, Ilya Poberezhskiy, Cory Powell, Giulio Rosanova, John Ruffa, Jeffrey Smith, Hong Tang, Christopher Tolman, Arthur Whipple, Timothy Wilson, Melissa Vess, Perry Voyer

Proceedings Volume 10698, 106982C (2018) https://doi.org/10.1117/12.2313748

KEYWORDS: Infrared telescopes, Space telescopes, Observatories, Telescopes, Infrared radiation, Optical instrument design, Infrared imaging, Exoplanets, Imaging spectroscopy, Coronagraphy

Read Abstract +

Proceedings Article | 19 September 2017 Presentation

Phase-induced amplitude apodization complex mask coronagraphy (PIAACMC) for large segmented apertures (Conference Presentation)

Olivier Guyon, Brian Kern, Alexander Rodack, Justin Knight, Ruslan Belikov, Dan Sirbu, Stephen Bryson, Christopher Henze, Johanan Codona, Stuart Shaklan

Proceedings Volume 10400, 104000K (2017) https://doi.org/10.1117/12.2274616

KEYWORDS: Image segmentation, Exoplanets, Imaging spectroscopy, Coronagraphy, Imaging systems, Stars, Diffraction, Apodization, Control systems, Colorimetry

Read Abstract +

Proceedings Article | 1 September 2017 Presentation + Paper

Hybrid Lyot coronagraph for WFIRST: high-contrast broadband testbed demonstration

Byoung-Joon Seo, Eric Cady, Brian Gordon, Brian Kern, Raymond Lam, David Marx, Dwight Moody, Richard Muller, Keith Patterson, Ilya Poberezhskiy, Camilo Mejia Prada, Erkin Sidick, Fang Shi, John Trauger, Daniel Wilson

Proceedings Volume 10400, 104000F (2017) https://doi.org/10.1117/12.2274687

KEYWORDS: Wavefronts, Infrared telescopes, Wavefront sensors, Infrared radiation, Space telescopes, Telescopes, Exoplanets, Metals, Dielectrics, Deformable mirrors

Read Abstract +

Proceedings Article | 1 September 2017 Paper

Shaped pupil coronagraphy for WFIRST: high-contrast broadband testbed demonstration

Eric Cady, Kunjithapatham Balasubramanian, Jessica Gersh-Range, Jeremy Kasdin, Brian Kern, Raymond Lam, Camilo Mejia Prada, Dwight Moody, Keith Patterson, Ilya Poberezhskiy, A. J. Eldorado Riggs, Byoung-Joon Seo, Fang Shi, Hong Tang, John Trauger, Hanying Zhou, Neil Zimmerman

Proceedings Volume 10400, 104000E (2017) https://doi.org/10.1117/12.2272834

KEYWORDS: Wavefronts, Coronagraphy, Exoplanets, Wavefront sensors, Performance modeling, Systems modeling, Control systems

Read Abstract +

Proceedings Article | 1 September 2017 Presentation + Paper

Wavefront control performance modeling with WFIRST shaped pupil coronagraph testbed

Hanying Zhou, Bijian Nemati, John Krist, Eric Cady, Brian Kern, Ilya Poberezhskiy

Proceedings Volume 10400, 1040005 (2017) https://doi.org/10.1117/12.2274391

KEYWORDS: Performance modeling, Wavefronts, Wavefront sensors, Control systems, Systems modeling, Exoplanets, Monte Carlo methods, Imaging systems, Space telescopes, Stars

Read Abstract +

Proceedings Article | 1 September 2017 Presentation + Paper

Sensitivity of WFIRST coronagraph broadband contrast performance to DM actuator errors

Erkin Sidick, Byoung-Joon Seo, Brian Kern, Ilya Poberezhskiy, Bijan Nemati, John Trauger

Proceedings Volume 10400, 1040006 (2017) https://doi.org/10.1117/12.2274421

KEYWORDS: Actuators, Deformable mirrors, Space telescopes, Exoplanets, Coronagraphy, Adaptive optics, Performance modeling, Wavefronts, Control systems, Interferometry

Read Abstract +

Proceedings Article | 1 September 2017 Paper

Optimizing the regularization in broadband wavefront control algorithm for WFIRST coronagraph

Erkin Sidick, Byoung-Joon Seo, Brian Kern, David Marx, Ilya Poberezhskiy, Bijan Nemati

Proceedings Volume 10400, 1040022 (2017) https://doi.org/10.1117/12.2274440

KEYWORDS: Coronagraphy, Performance modeling, Modeling and simulation, Wavefronts, Deformable mirrors, Space telescopes, Exoplanets, Process control, Control systems, Adaptive optics

Read Abstract +

Proceedings Article | 1 September 2017 Presentation + Paper

Electric field conjugation in the presence of model uncertainty

David Marx, Byoung-Joon Seo, Brian Kern, Erkin Sidick, Bijan Nemati, Ilya Poberezhskiy

Proceedings Volume 10400, 104000P (2017) https://doi.org/10.1117/12.2274541

KEYWORDS: Calibration, Space telescopes, Point spread functions, Imaging systems, Adaptive optics, Deformable mirrors, Infrared telescopes, Data modeling, Coronagraphy, Nonlinear optics

Read Abstract +

Proceedings Article | 1 September 2017 Presentation + Paper

Dynamic testbed demonstration of WFIRST coronagraph low order wavefront sensing and control (LOWFS/C)

Fang Shi, Eric Cady, Byoung-Joon Seo, Xin An, Kunjithapatham Balasubramanian, Brian Kern, Raymond Lam, David Marx, Dwight Moody, Camilo Mejia Prada, Keith Patterson, Ilya Poberezhskiy, Joel Shields, Erkin Sidick, Hong Tang, John Trauger, Tuan Truong, Victor White, Daniel Wilson, Hanying Zhou

Proceedings Volume 10400, 104000D (2017) https://doi.org/10.1117/12.2274887

KEYWORDS: Wavefront sensors, Wavefronts, Mirrors, Deformable mirrors, Environmental sensing, Phase shifting, Optical telescopes, Optical fabrication, Device simulation, Space telescopes

Read Abstract +

Proceedings Article | 29 July 2016 Paper

Closing the contrast gap between testbed and model prediction with WFIRST-CGI shaped pupil coronagraph

Hanying Zhou, Bijan Nemati, John Krist, Eric Cady, Camilo Prada, Brian Kern, Ilya Poberezhskiy

Proceedings Volume 9904, 990419 (2016) https://doi.org/10.1117/12.2232211

KEYWORDS: Speckle, Actuators, Error control coding, Coronagraphy, Wavefronts, Error analysis, Control systems, Data modeling, Monochromatic aberrations, Phase measurement

Read Abstract +

Proceedings Article | 29 July 2016 Paper

Low-signal, coronagraphic wavefront estimation with Kalman filtering in the high contrast imaging testbed

A J Eldorado Riggs, Eric Cady, Camilo Prada, Brian Kern, Hanying Zhou, N. Jeremy Kasdin, Tyler Groff

Proceedings Volume 9904, 99043F (2016) https://doi.org/10.1117/12.2233909

KEYWORDS: Wavefronts, Infrared telescopes, Space telescopes, Telescopes, Coronagraphy, Point spread functions, Exoplanets, Image analysis, Planets, Signal to noise ratio

Read Abstract +

SPIE Journal Paper | 8 March 2016

Hybrid Lyot coronagraph for wide-field infrared survey telescope-astrophysics focused telescope assets: occulter fabrication and high contrast narrowband testbed demonstration

Byoung-Joon Seo, Brian Gordon, Brian Kern, Andreas Kuhnert, Dwight Moody, Richard Muller, Ilya Poberezhskiy, John Trauger, Daniel Wilson

JATIS, Vol. 2, Issue 01, 011019, (March 2016) https://doi.org/10.1117/12.10.1117/1.JATIS.2.1.011019

KEYWORDS: Coronagraphy, Telescopes, Infrared telescopes, Space telescopes, Nickel, Astronomical telescopes, Infrared radiation, Dielectrics, Actuators, Photomasks

Read Abstract +

SPIE Journal Paper | 28 January 2016

Phase-induced amplitude apodization complex mask coronagraph mask fabrication, characterization, and modeling for WFIRST-AFTA

Brian Kern, Olivier Guyon, Ruslan Belikov, Daniel Wilson, Richard Muller, Erkin Sidick, Bala Balasubramanian, John Krist, Ilya Poberezhskiy, Hong Tang

JATIS, Vol. 2, Issue 01, 011014, (January 2016) https://doi.org/10.1117/12.10.1117/1.JATIS.2.1.011014

KEYWORDS: Planets, Coronagraphy, Wavefronts, Apodization, Scanning electron microscopy, Mask making, Atomic force microscopy, Reflectivity, Mirrors, Polymethylmethacrylate

Read Abstract +

SPIE Journal Paper | 27 January 2016

Impact of WFIRST-AFTA line-of-sight jitter distributions on phase-induced amplitude apodization complex mask coronagraph science yield

Brian Kern

JATIS, Vol. 2, Issue 01, 011016, (January 2016) https://doi.org/10.1117/12.10.1117/1.JATIS.2.1.011016

KEYWORDS: Cameras, Planets, Coronagraphy, Signal to noise ratio, Solids, Point spread functions, Apodization, Wavefronts, Stars, Spectroscopy

Read Abstract +

SPIE Journal Paper | 17 December 2015 Open Access

Methods and limitations of focal plane sensing, estimation, and control in high-contrast imaging

Tyler Groff, A. J. Eldorado Riggs, Brian Kern, N. Jeremy Kasdin

JATIS, Vol. 2, Issue 01, 011009, (December 2015) https://doi.org/10.1117/12.10.1117/1.JATIS.2.1.011009

KEYWORDS: Imaging systems, Control systems, Wavefronts, Error analysis, Coronagraphy, Speckle, Sensing systems, Filtering (signal processing), Actuators, Space telescopes

Read Abstract +

DOWNLOAD PAPER

SPIE Journal Paper | 7 December 2015

WFIRST-AFTA coronagraph shaped pupil masks: design, fabrication, and characterization

Kunjithapatham Balasubramanian, Victor White, Karl Yee, Pierre Echternach, Richard Muller, Matthew Dickie, Eric Cady, Camilo Prada, Daniel Ryan, Ilya Poberezhskiy, Brian Kern, Hanying Zhou, John Krist, Bijan Nemati, A. J. Eldorado Riggs, Neil Zimmerman, N. Jeremy Kasdin

JATIS, Vol. 2, Issue 01, 011005, (December 2015) https://doi.org/10.1117/12.10.1117/1.JATIS.2.1.011005

KEYWORDS: Photomasks, Silicon, Coronagraphy, Reflectivity, Semiconducting wafers, Aluminum, Point spread functions, Wavefronts, Optical instrument design, Etching

Read Abstract +

SPIE Journal Paper | 28 October 2015

Demonstration of high contrast with an obscured aperture with the WFIRST-AFTA shaped pupil coronagraph

Eric Cady, Camilo Mejia Prada, Xin An, Kunjithapatham Balasubramanian, Rosemary Diaz, N. Jeremy Kasdin, Brian Kern, Andreas Kuhnert, Bijan Nemati, Ilya Poberezhskiy, A. J. Eldorado Riggs, Robert Zimmer, Neil Zimmerman

JATIS, Vol. 2, Issue 01, 011004, (October 2015) https://doi.org/10.1117/12.10.1117/1.JATIS.2.1.011004

KEYWORDS: Coronagraphy, Photomasks, Planets, Point spread functions, Telescopes, Infrared telescopes, Semiconducting wafers, Reflectivity, Wavefronts, Data modeling

Read Abstract +

The coronagraph instrument on the Wide-Field Infrared Survey Telescope-Astrophysics-Focused Telescope Asset (WFIRST-AFTA) mission study has two coronagraphic architectures, shaped pupil and hybrid Lyot, which may be interchanged for use in different observing scenarios. Each architecture relies on newly developed mask components to function in the presence of the AFTA aperture, and so both must be matured to a high technology readiness level in advance of the mission. A series of milestones were set to track the development of the technologies required for the instrument; we report on completion of WFIRST-AFTA coronagraph milestone 2—a narrowband 10−8 contrast test with static aberrations for the shaped pupil—and the plans for the upcoming broadband coronagraph milestone 5.

Proceedings Article | 16 September 2015

Laboratory performance of the shaped pupil coronagraphic architecture for the WFIRST/AFTA coronagraph

Eric Cady, Camilo Mejia Prada, Xin An, Kunjithapatham Balasubramanian, Rosemary Diaz, N. Jeremy Kasdin, Brian Kern, Andreas Kuhnert, Bijan Nemati, Keith Patterson, Ilya Poberezhskiy, A. J. Eldorado Riggs, Daniel Ryan, Hanying Zhou, Robert Zimmer, Neil Zimmerman

Proceedings Volume 9605, 96050B (2015) https://doi.org/10.1117/12.2189113

KEYWORDS: Coronagraphy, Photomasks, Telescopes, Point spread functions, Microscopes, Infrared telescopes, Silicon, Binary data, Infrared radiation, Stars

Read Abstract +

One of the two primary architectures being tested for the WFIRST-AFTA coronagraph instrument is the shaped pupil coronagraph, which uses a binary aperture in a pupil plane to create localized regions of high contrast in a subsequent focal plane. The aperture shapes are determined by optimization, and can be designed to work in the presence of secondary obscurations and spiders - an important consideration for coronagraphy with WFIRST-AFTA. We present the current performance of the shaped pupil testbed, including the results of AFTA Milestone 2, in which ≈ 6 × 10^-9 contrast was achieved in three independent runs starting from a neutral setting.

Proceedings Article | 16 September 2015

Low order wavefront sensing and control for WFIRST-AFTA coronagraph

Fang Shi, Kunjithapatham Balasubramanian, Randall Bartos, Randall Hein, Brian Kern, John Krist, Raymond Lam, Douglas Moore, James Moore, Keith Patterson, Ilya Poberezhskiy, Joel Shields, Erkin Sidick, Hong Tang, Tuan Truong, Kent Wallace, Xu Wang, Dan Wilson

Proceedings Volume 9605, 960509 (2015) https://doi.org/10.1117/12.2188775

KEYWORDS: Coronagraphy, Wavefronts, Wavefront sensors, Actuators, Telescopes, Calibration, Sensors, Mirrors, Monochromatic aberrations, Space telescopes

Read Abstract +

To maintain the required WFIRST Coronagraph starlight suppression performance in a realistic space environment, a low order wavefront sensing and control (LOWFS/C) subsystem is necessary. The LOWFS/C uses the rejected stellar light from coronagraph to sense and suppress the telescope pointing drift and jitter as well as the low order wavefront errors due to changes in thermal loading on the telescope and the rest of the observatory. In this paper we will present an overview of the low order wavefront sensing and control subsystem for the WFIRST Coronagraph. We will describe LOWFS/C’s Zernike wavefront sensor concept and control design, and present an overview of sensing performance analysis and modeling, predicted line-of-sight jitter suppression loop performance, as well as the low order wavefront error correction with the coronagraph’s deformable mirror. We will also report the LOWFS/C testbed design and the preliminary in-air test results, which show promising performance of the Zernike wavefront sensor and FSM feedback loop.

Proceedings Article | 16 September 2015

Exoplanet coronagraph shaped pupil masks and laboratory scale star shade masks: design, fabrication and characterization

Kunjithapatham Balasubramanian, Victor White, Karl Yee, Pierre Echternach, Richard Muller, Matthew Dickie, Eric Cady, Camilo Mejia Prada, Daniel Ryan, Ilya Poberezhskiy, Hanying Zhou, Brian Kern, A. J. Riggs, Neil Zimmerman, Dan Sirbu, Stuart Shaklan, Jeremy Kasdin

Proceedings Volume 9605, 96050L (2015) https://doi.org/10.1117/12.2188954

KEYWORDS: Photomasks, Silicon, Reflectivity, Aluminum, Coronagraphy, Semiconducting wafers, Stars, Wavefronts, Point spread functions, Telescopes

Read Abstract +

Star light suppression technologies to find and characterize faint exoplanets include internal coronagraph instruments as well as external star shade occulters. Currently, the NASA WFIRST-AFTA mission study includes an internal coronagraph instrument to find and characterize exoplanets. Various types of masks could be employed to suppress the host star light to about 10^-9 level contrast over a broad spectrum to enable the coronagraph mission objectives. Such masks for high contrast internal coronagraphic imaging require various fabrication technologies to meet a wide range of specifications, including precise shapes, micron scale island features, ultra-low reflectivity regions, uniformity, wave front quality, achromaticity, etc. We present the approaches employed at JPL to produce pupil plane and image plane coronagraph masks by combining electron beam, deep reactive ion etching, and black silicon technologies with illustrative examples of each, highlighting milestone accomplishments from the High Contrast Imaging Testbed (HCIT) at JPL and from the High Contrast Imaging Lab (HCIL) at Princeton University. We also present briefly the technologies applied to fabricate laboratory scale star shade masks.

Proceedings Article | 11 September 2015

Prototype imaging spectrograph for coronagraphic exoplanet studies (PISCES) for WFIRST/AFTA

Qian Gong, Michael McElwain, Bradford Greeley, Bryan Grammer, Catherine Marx, Nargess Memarsadeghi, Karl Stapelfeldt, George Hilton, Jorge Llop Sayson, Marshall Perrin, Richard Demers, Hong Tang, Brian Kern, Janan Ferdosi

Proceedings Volume 9605, 96050G (2015) https://doi.org/10.1117/12.2187122

KEYWORDS: Iterated function systems, Coronagraphy, Prisms, Reflectivity, Optical alignment, Sensors, Spectrographs, Spectroscopy, Relays, Mirrors

Read Abstract +

Prototype Imaging Spectrograph for Coronagraphic Exoplanet Studies (PISCES) is a lenslet array based integral field spectrometer (IFS) designed for high contrast imaging of extrasolar planets. PISCES will be used to advance the technology readiness of the high contrast IFS baselined on the Wide-Field InfraRed Survey Telescope/Astrophysics Focused Telescope Assets (WFIRST-AFTA) coronagraph instrument. PISCES will be integrated into the high contrast imaging testbed (HCIT) at the Jet Propulsion Laboratory (JPL) and will work with both the Hybrid Lyot Coronagraph (HLC) and the Shaped Pupil Coronagraph (SPC) configurations. We discuss why the lenslet array based IFS was selected for PISCES. We present the PISCES optical design, including the similarities and differences of lenslet based IFSs to normal spectrometers, the trade-off between a refractive design and reflective design, as well as the specific function of our pinhole mask on the back surface of the lenslet array to reduce the diffraction from the edge of the lenslets. The optical analysis, alignment plan, and mechanical design of the instrument will be discussed.

Proceedings Article | 2 August 2014

Technology development towards WFIRST-AFTA coronagraph

Ilya Poberezhskiy, Feng Zhao, Xin An, Kunjithapatham Balasubramanian, Ruslan Belikov, Eric Cady, Richard Demers, Rosemary Diaz, Qian Gong, Brian Gordon, Renaud Goullioud, Frank Greer, Olivier Guyon, Michael Hoenk, N. Jeremy Kasdin, Brian Kern, John Krist, Andreas Kuhnert, Michael McElwain, Bertrand Mennesson, Dwight Moody, Richard Muller, Bijan Nemati, Keith Patterson, A. J. Riggs, Daniel Ryan, Byoung-Joon Seo, Stuart Shaklan, Erkin Sidick, Fang Shi, Nicholas Siegler, Rémi Soummer, Hong Tang, John Trauger, J. Kent Wallace, Xu Wang, Victor White, Daniel Wilson, Karl Yee, Hanying Zhou, Neil Zimmerman

Proceedings Volume 9143, 91430P (2014) https://doi.org/10.1117/12.2060320

KEYWORDS: Coronagraphy, Sensors, Wavefronts, Wavefront sensors, Iterated function systems, Photomasks, Space telescopes, Exoplanets, Deformable mirrors, Planets

Read Abstract +

NASA’s WFIRST-AFTA mission concept includes the first high-contrast stellar coronagraph in space. This coronagraph will be capable of directly imaging and spectrally characterizing giant exoplanets similar to Neptune and Jupiter, and possibly even super-Earths, around nearby stars. In this paper we present the plan for maturing coronagraph technology to TRL5 in 2014-2016, and the results achieved in the first 6 months of the technology development work. The specific areas that are discussed include coronagraph testbed demonstrations in static and simulated dynamic environment, design and fabrication of occulting masks and apodizers used for starlight suppression, low-order wavefront sensing and control subsystem, deformable mirrors, ultra-low-noise spectrograph detector, and data post-processing.

Proceedings Article | 2 August 2014

Simulated contrast performance of Phase Induced Amplitude Apodization (PIAA) coronagraph testbed

Erkin Sidick, Brian Kern, Ruslan Belikov, Andreas Kuhnert, Stuart Shaklan

Proceedings Volume 9143, 91430W (2014) https://doi.org/10.1117/12.2055006

KEYWORDS: Coronagraphy, Wavefronts, Actuators, Mirrors, Apodization, Point spread functions, Device simulation, Modeling and simulation, Source mask optimization, Control systems

Read Abstract +

We evaluate the broadband contrast performance of a Phase Induced Amplitude Apodization (PIAA) coronagraph configuration through modeling and simulations. Broadband occulter mask design for PIAA-CMC is at an early stage, and a study of the effects of wavefront control on broadband contrast is needed to determine the level of control the occulting mask must achieve, so that the combination of occulter and wavefront control optimization meets contrast targets. The basic optical design of the PIAA coronagraph is the same as NASA’s High Contrast Imaging Testbed (HCIT) setup at the Jet Propulsion Laboratory (JPL). Using two deformable mirrors and a broadband wavefront sensing and control algorithm, we create a “dark hole” in the broadband point-spread function (PSF) with an inner working angle (IWA) of 2(fλ/D)_sky. We evaluate a system using PIAA mirrors to create an apodization but not having any wavefront error at its exit-pupil, and having an obscured pupil and a new, 20-ring PIAACMC occulting mask. We also investigate the effect of Lyot stops of various sizes. For the configuration simulated here with the second-generation PIAA mirrors and early mask designs (which were not yet fully optimized), the best 10% broadband contrast value was ~6.1×10^-8. This is a 2x improvement beyond what the coronagraph produces in the absence of wavefront control, which implies that further improvement must come from architecture changes or further mask optimization improvements.

Proceedings Article | 26 September 2013

HCIT contrast performance sensitivity studies: simulation versus experiment

Erkin Sidick, Stuart Shaklan, John Krist, Eric Cady, Brian Kern, Kunjithapatham Balasubramanian

Proceedings Volume 8864, 88640Q (2013) https://doi.org/10.1117/12.2024516

KEYWORDS: Coronagraphy, Opacity, Actuators, Systems modeling, Wavefronts, Cesium, 3D modeling, Exoplanets, Optical simulations, Device simulation

Read Abstract +

Using NASA’s High Contrast Imaging Testbed (HCIT) at the Jet Propulsion Laboratory, we have experimentally investigated the sensitivity of dark hole contrast in a Lyot coronagraph for the following factors: 1) Lateral and longitudinal translation of an occulting mask; 2) An opaque spot on the occulting mask; 3) Sizes of the controlled dark hole area. Also, we compared the measured results with simulations obtained using both MACOS (Modeling and Analysis for Controlled Optical Systems) and PROPER optical analysis programs with full three-dimensional near-field diffraction analysis to model HCIT’s optical train and coronagraph.

Proceedings Article | 26 September 2013

High contrast internal and external coronagraph masks produced by various techniques

Kunjithapatham Balasubramanian, Daniel Wilson, Victor White, Richard Muller, Matthew Dickie, Karl Yee, Ronald Ruiz, Stuart Shaklan, Eric Cady, Brian Kern, Ruslan Belikov, Olivier Guyon, N. Jeremy Kasdin

Proceedings Volume 8864, 88641R (2013) https://doi.org/10.1117/12.2024615

KEYWORDS: Photomasks, Coronagraphy, Silicon, Reflectivity, Ion beams, Deep reactive ion etching, Telescopes, Fabrication, Electron beam lithography, Scanning electron microscopy

Read Abstract +

High contrast internal and external coronagraphic imaging requires a variety of masks depending on different architectures to suppress star light. Various fabrication technologies are required to address a wide range of needs including gradient amplitude transmission, tunable phase profiles, ultra-low reflectivity, precise small scale features, and low-chromaticity. We present the approaches employed at JPL to produce pupil plane and image plane coronagraph masks, and lab-scale external occulter type masks by various techniques including electron beam, ion beam, deep reactive ion etching, and black silicon technologies with illustrative examples of each. Further development is in progress to produce circular masks of various kinds for obscured aperture telescopes.

Proceedings Article | 26 September 2013

Demonstration of symmetric dark holes using two deformable mirrors at the high-contrast imaging testbed

A. J. Eldorado Riggs, Tyler Groff, Alexis Carlotti, N. Jeremy Kasdin, Eric Cady, Brian Kern, Andreas Kuhnert

Proceedings Volume 8864, 88640T (2013) https://doi.org/10.1117/12.2024278

KEYWORDS: Wavefronts, Actuators, Filtering (signal processing), Point spread functions, Surface plasmons, Coronagraphy, Photomasks, Deformable mirrors, Exoplanets, Manufacturing

Read Abstract +

The High Contrast Imaging Laboratory (HCIL) at Princeton has developed several important algorithms and technologies for space-based coronagraphy missions to detect earth-like exoplanets. Before June 2013 the HCIL was the only facility with two deformable mirrors (DMs) in series for focal plane wavefront control, which allows for quasi-static speckle correction on both sides of the image plane. From June through August 2013, the High- Contrast Imaging Testbed (HCIT) at JPL had a second DM installed. In this paper we report on the results of our Technology Development for Exoplanet Missions project to achieve high contrast in two symmetric dark holes using a shaped pupil (SP) coronagraph at the HCIT. Our previous experiment with a similar SP at the HCIT in 2007 yielded single-sided dark holes. That experiment utilized an iterative, batch-process wavefront estimator and Electric Field Conjugation for wavefront control. Our current tests use the faster Kalman filter estimator and the stroke minimization control algorithm. We use the same ripple-style SPs as in the previous HCIT experiment because that mask manufacturing technique proved successful. Our tests of symmetric dark holes in monochromatic light at the HCIT demonstrate Princeton’s steady improvements in wavefront control and estimation techniques for a space-based coronagraphy mission.

Proceedings Article | 26 September 2013

High-contrast imaging results with the vortex coronagraph

E. Serabyn, J. Trauger, D. Moody, D. Mawet, K. Liewer, J. Krist, B. Kern

Proceedings Volume 8864, 88640Y (2013) https://doi.org/10.1117/12.2024660

KEYWORDS: Coronagraphy, Light, Polarization, Wave plates, Stars, Space telescopes, Cameras, Polarizers, Point spread functions, Speckle

Read Abstract +

The vortex coronagraph has already enabled high-contrast observations very close to bright stars on large ground-based telescopes, and it also has great potential for use on coronagraphic space missions aimed at exoplanet detection and characterization. As such, demonstrations of vortex coronagraph performance have recently been carried out in JPL’s High Contrast Imaging Testbed. Some of our recent results are presented here, including the suppression of a monochromatic, single-polarization point-source to below the 10^-9 level over a dark hole covering both the 2-7 λ/D and 3-8 λ/D regions, as well as the suppression of a 10% band of white-light to approximately the 10^-8 level over a 3-8 λ/D dark hole.

Proceedings Article | 26 September 2013

Survey of experimental results in high-contrast imaging for future exoplanet missions

P. Lawson, R. Belikov, W. Cash, M. Clampin, T. Glassman, O. Guyon, N. J. Kasdin, B. Kern, R. Lyon, D. Mawet, D. Moody, R. Samuele, E. Serabyn, D. Sirbu, J. Trauger

Proceedings Volume 8864, 88641F (2013) https://doi.org/10.1117/12.2021302

KEYWORDS: Coronagraphy, Exoplanets, Stars, Planets, Polarizers, Deformable mirrors, Manufacturing, Optics manufacturing, Image segmentation, Imaging systems

Read Abstract +

We present and compare experimental results in high contrast imaging representing the state of the art in coronagraph and starshade technology. These experiments have been undertaken with the goal of demonstrating the capability of detecting Earth-like planets around nearby Sun-like stars. The contrast of an Earth seen in reflected light around a Sun-like star would be about 1.2 × 10⁻¹⁰. Several of the current candidate technologies now yield raw contrasts of 1.0 × 10⁻⁹ or better, and so should enable the detection of Earths, assuming a gain in sensitivity in post-processing of a factor of 10. We present results of coronagraph and starshade experiments conducted at visible and infrared wavelengths. Cross-sections of dark fields are directly compared as a function of field angle and bandwidth. The strength and differences of the techniques are compared.

Proceedings Article | 26 September 2013

Laboratory demonstration of Phase Induced Amplitude Apodization (PIAA) coronagraph with better than 10-9 contrast

Brian Kern, Olivier Guyon, Andreas Kuhnert, Albert Niessner, Frantz Martinache, Kunjithapatham Balasubramanian

Proceedings Volume 8864, 88640R (2013) https://doi.org/10.1117/12.2022929

KEYWORDS: Coronagraphy, Cameras, Wavefronts, Mirrors, Control systems, Apodization, Actuators, Linear polarizers, Deformable mirrors, Imaging spectroscopy

Read Abstract +

We present coronagraphic images from the Phase Induced Amplitude Apodization (PIAA) coronagraph on NASA's High Contrast Imaging Testbed (HCIT) at the Jet Propulsion Lab, showing contrasts of 5×10⁻¹⁰ averaged from 2-4 λ/D, in monochromatic light at 808 nm. In parallel with the coronagraph and its deformable mirror and coronagraphic wavefront control, we also demonstrate a low-order wavefront control system, giving 100× rms suppression of introduced tip/tilt disturbances down to residual levels of 10⁻³ λ/D. Current limitations, as well as broadband (10% fractional bandpass) preliminary results are discussed.

Proceedings Article | 26 September 2013

Comparison of simulated contrast performance of different Phase Induced Amplitude Apodization (PIAA) coronagraph configurations

Erkin Sidick, Brian Kern, Andreas Kuhnert, Stuart Shaklan

Proceedings Volume 8864, 88641Y (2013) https://doi.org/10.1117/12.2035237

KEYWORDS: Point spread functions, Coronagraphy, Actuators, Wavefronts, Francium, Apodization, Mirrors, Device simulation, Control systems, Modeling and simulation

Read Abstract +

We compare the broadband contrast performances of several Phase Induced Amplitude Apodization (PIAA) coronagraph configurations through modeling and simulations. The basic optical design of the PIAA coronagraph is the same as NASA’s High Contrast Imaging Testbed (HCIT) setup at the Jet Propulsion Laboratory (JPL). Using a deformable mirror and a broadband wavefront sensing and control algorithm, we create a 'dark hole' in the broadband point-spread function (PSF) with an inner working angle (IWA) of 2(fλ/D)_sky. We evaluate two systems in parallel. One is a perfect system having a design PIAA output amplitude and not having any wavefront error at its exit-pupil. The other is a realistic system having a design PIAA output amplitude and the measured residual wavefront error. We also investigate the effect of Lyot stops of various sizes when a postapodizer is and is not present. For the configurations simulated here with the first-generation PIAA mirrors, the best 7.5% broadband contrast value was ~1.5×10^-8.

Proceedings Article | 21 September 2012

Electric field reconstruction in the image plane of a high-contrast coronagraph using a set of pinholes around the Lyot plane

Amir Give'on, Stuart Shaklan, Brian Kern, Charley Noecker, Steve Kendrick, Kent Wallace

Proceedings Volume 8442, 84420B (2012) https://doi.org/10.1117/12.927120

KEYWORDS: Calibration, Coronagraphy, Speckle, Condition numbers, Planets, Deformable mirrors, Cameras, Composites, Wavefronts, Image compression

Read Abstract +

In a setup similar to the self coherent camera, we have added a set of pinholes in the diffraction ring of the Lyot plane in a high-contrast stellar Lyot coronagraph. We describe a novel complex electric field reconstruction from image plane intensity measurements consisting of light in the coronagraph's dark hole interfering with light from the pinholes. The image plane field is modified by letting light through one pinhole at a time. In addition to estimation of the field at the science camera, this method allows for self-calibration of the probes by letting light through the pinholes in various permutations while blocking the main Lyot opening. We present results of estimation and calibration from the High Contrast Imaging Testbed along with a comparison to the pair-wise deformable mirror diversity based estimation technique. Tests are carried out in narrow-band light and over a composite 10% bandpass.

Proceedings Article | 21 September 2012

Phase induced amplitude apodization (PIAA) coronagraphy: recent results and future prospects

Olivier Guyon, Brian Kern, Ruslan Belikov, Stuart Shaklan, Andreas Kuhnert, Amir Give'on, Frantz Martinache

Proceedings Volume 8442, 84424V (2012) https://doi.org/10.1117/12.927187

KEYWORDS: Coronagraphy, Apodization, Telescopes, Space telescopes, Aspheric optics, Exoplanets, Stars, Optics manufacturing, Calibration, Planets

Read Abstract +

Thanks to the use of aspheric optics for lossless apodization, the Phase Induced Amplitude Apodization (PIAA) coronagraph offers full throughput, high contrast and small inner working angle. It is therefore ideally suited for space-based direct imaging of potentially habitable exoplanets. The concept has evolved since its original formulation to mitigate manufacturing challenges and improve performance. Our group is currently aiming at demonstrating PIAA coronagraphy in the laboratory to 1e-9 raw contrast at 2 λ/D separation. Recent results from the High Contrast Imaging Testbed (HCIT) at JPL demonstrate contrasts about one order of magnitude from this goal at 2 λ/D. In parallel with our high contrast demonstration at 2 λ/D, we are developing and testing new designs to reduce inner working angle and improve performance in polychromatic light. The newly developed PIAA complex mask coronagraph (PIAACMC) concept provides total starlight extinction and offers full throughput with a sub- λ/D inner working angles. We also describe a recent laboratory demonstration of fine pointing control with PIAA.

Proceedings Article | 21 September 2012

Coronagraph focal-plane phase masks based on photonic crystal technology: recent progress and observational strategy

Naoshi Murakami, Jun Nishikawa, Wesley Traub, Dimitri Mawet, Dwight Moody, Brian Kern, John Trauger, Eugene Serabyn, Shoki Hamaguchi, Fumika Oshiyama, Moritsugu Sakamoto, Akitoshi Ise, Kazuhiko Oka, Naoshi Baba, Hiroshi Murakami, Motohide Tamura

Proceedings Volume 8442, 844205 (2012) https://doi.org/10.1117/12.925613

KEYWORDS: Coronagraphy, Polarization, Photonic crystals, Manufacturing, Photomasks, Stars, Polarimetry, Spiral phase plates, Phase shift keying, Planets

Read Abstract +

Photonic crystal, an artificial periodic nanostructure of refractive indices, is one of the attractive technologies for coronagraph focal-plane masks aiming at direct imaging and characterization of terrestrial extrasolar planets. We manufactured the eight-octant phase mask (8OPM) and the vector vortex coronagraph (VVC) mask very precisely using the photonic crystal technology. Fully achromatic phase-mask coronagraphs can be realized by applying appropriate polarization filters to the masks. We carried out laboratory experiments of the polarization-filtered 8OPM coronagraph using the High-Contrast Imaging Testbed (HCIT), a state-of-the-art coronagraph simulator at the Jet Propulsion Laboratory (JPL). We report the experimental results of 10^-8-level contrast across several wavelengths over 10% bandwidth around 800nm. In addition, we present future prospects and observational strategy for the photonic-crystal mask coronagraphs combined with differential imaging techniques to reach higher contrast. We proposed to apply the polarization-differential imaging (PDI) technique to the VVC, in which we built a two-channel coronagraph using polarizing beam splitters to avoid a loss of intensity due to the polarization filters. We also proposed to apply the angular-differential imaging (ADI) technique to the 8OPM coronagraph. The 8OPM/ADI mode mitigates an intensity loss due to a phase transition of the mask and provides a full field of view around central stars. We present results of preliminary laboratory demonstrations of the PDI and ADI observational modes with the phase-mask coronagraphs.

Proceedings Article | 15 September 2011

Advanced speckle sensing for internal coronagraphs

Charley Noecker, Stuart Shaklan, James Wallace, Brian Kern, Amir Give'on, Jeremy Kasdin, Ruslan Belikov, Steve Kendrick

Proceedings Volume 8151, 81510I (2011) https://doi.org/10.1117/12.895544

KEYWORDS: Speckle, Calibration, Exoplanets, Stars, Planets, Coronagraphy, Telescopes, Wavefronts, Space telescopes, Signal to noise ratio

Read Abstract +

A 4-8m diameter telescope carrying a coronagraph instrument is a leading candidate for an anticipated flagship mission to detect and characterize Earth-size exoplanets in the 2020s.1 Many candidate coronagraph instruments have been proposed, and one is close to meeting some of the principal requirements for that mission. But the telescope and instrument will need exquisite stability and precise control of the incoming wavefront to enable detection of faint companions (10^-10of the star) at an angular separation of 2-4 Airy radii. In particular, wavefront errors cause speckles in the image, and variations in those speckles can confound the exoplanet detection. This challenge is compounded by the background light from zodiacal dust around our Sun and the target star, which limits the speed with which we can estimate and correct the speckles. We are working on developing coherent speckle detection techniques that will allow rapid calibration of speckles on the science detector, allowing subtraction in post-processing or correction with deformable mirrors. The expected speed improvement allows a much quicker timeline for measurement & calibration, which reduces the required telescope stability requirement and eases both the flight system design and the challenge of ground testing. We will describe the experiments and summarize progress to date.

Proceedings Article | 15 September 2011

Taking the vector vortex coronagraph to the next level for ground- and space-based exoplanet imaging instruments: review of technology developments in the USA, Japan, and Europe

Dimitri Mawet, Naoshi Murakami, Christian Delacroix, Eugene Serabyn, Olivier Absil, Naoshi Baba, Jacques Baudrand, Anthony Boccaletti, Rick Burruss, Russell Chipman, Pontus Forsberg, Serge Habraken, Shoki Hamaguchi, Charles Hanot, Akitoshi Ise, Mikael Karlsson, Brian Kern, John Krist, Andreas Kuhnert, Marie Levine, Kurt Liewer, Stephen McClain, Scott McEldowney, Bertrand Mennesson, Dwight Moody, Hiroshi Murakami, Albert Niessner, Jun Nishikawa, Nada O'Brien, Kazuhiko Oka, Peggy Park, Pierre Piron, Laurent Pueyo, Pierre Riaud, Moritsugu Sakamoto, Motohide Tamura, John Trauger, David Shemo, Jean Surdej, Nelson Tabirian, Wesley Traub, James Wallace, Kaito Yokochi

Proceedings Volume 8151, 815108 (2011) https://doi.org/10.1117/12.896059

KEYWORDS: Coronagraphy, Polarization, Spiral phase plates, Photonic crystals, Liquid crystals, Polymers, Telescopes, Exoplanets, Space telescopes, Optics manufacturing

Read Abstract +

The Vector Vortex Coronagraph (VVC) is one of the most attractive new-generation coronagraphs for ground- and space-based exoplanet imaging/characterization instruments, as recently demonstrated on sky at Palomar and in the laboratory at JPL, and Hokkaido University. Manufacturing technologies for devices covering wavelength ranges from the optical to the mid-infrared, have been maturing quickly. We will review the current status of technology developments supported by NASA in the USA (Jet Propulsion Laboratory-California Institute of Technology, University of Arizona, JDSU and BEAMCo), Europe (University of Li`ege, Observatoire de Paris- Meudon, University of Uppsala) and Japan (Hokkaido University, and Photonics Lattice Inc.), using liquid crystal polymers, subwavelength gratings, and photonics crystals, respectively. We will then browse concrete perspectives for the use of the VVC on upcoming ground-based facilities with or without (extreme) adaptive optics, extremely large ground-based telescopes, and space-based internal coronagraphs.

Proceedings Article | 15 September 2011

Pair-wise, deformable mirror, image plane-based diversity electric field estimation for high contrast coronagraphy

Amir Give'on, Brian Kern, Stuart Shaklan

Proceedings Volume 8151, 815110 (2011) https://doi.org/10.1117/12.895117

KEYWORDS: Coronagraphy, Cameras, Actuators, Deformable mirrors, Error analysis, Modulation, Wavefronts, Reconstruction algorithms, Algorithm development, Imaging systems

Read Abstract +

In this paper we describe the complex electric field reconstruction from image plane intensity measurements for high contrast coronagraphic imaging. A deformable mirror (DM) surface is modified with pairs of complementary shapes to create diversity in the image plane of the science camera where the intensity of the light is measured. Along with the Electric Field Conjugation correction algorithm, this estimation method has been used in various high contrast imaging testbeds to achieve the best contrasts to date both in narrow and in broad band light. We present the basic methodology of estimation in easy to follow list of steps, present results from HCIT and raise several open questions we are confronted with using this method.

Proceedings Article | 15 September 2011

Recent results of the second generation of vector vortex coronagraphs on the high-contrast imaging testbed at JPL

Dimitri Mawet, Eugene Serabyn, Dwight Moody, Brian Kern, Albert Niessner, Andreas Kuhnert, David Shemo, Russell Chipman, Stephen McClain, John Trauger

Proceedings Volume 8151, 81511D (2011) https://doi.org/10.1117/12.896070

KEYWORDS: Coronagraphy, Wavefronts, Colorimetry, Space telescopes, Polarizers, Actuators, Optical filters, Polarization, Exoplanets, Point spread functions

Read Abstract +

The Vector Vortex Coronagraph (VVC) is an attractive internal coronagraph solution to image and characterize exoplanets. It provides four key pillars on which efficient high contrast imaging instruments can be built for ground- and space-based telescopes: small inner working angle, high throughput, clear off-axis discovery space, and simple layout. We present the status of the VVC technology development supported by NASA. We will review recent results of the optical tests of the second-generation topological charge 4 VVC on the actively corrected High Contrast Imaging Testbed (HCIT) at the Jet Propulsion Laboratory (JPL). New VVC contrast records have been established.

Proceedings Article | 15 September 2011

Laboratory testing of a Phase-Induced Amplitude Apodization (PIAA) coronagraph

Brian Kern, Olivier Guyon, Amir Give'on, Andreas Kuhnert, Albert Niessner

Proceedings Volume 8151, 815104 (2011) https://doi.org/10.1117/12.896467

KEYWORDS: Wavefronts, Coronagraphy, Cameras, Mirrors, Actuators, Light, Apodization, Binary data, Optical testing, Deformable mirrors

Read Abstract +

We present high-contrast images from laboratory testing of a Phase Induced Amplitude Apodization (PIAA) coronagraph at NASA's High Contrast Imaging Testbed (HCIT). Using a deformable mirror and wavefront estimation and control algorithms, we create a "dark hole" in the monochromatic point-spread function with an inner working angle of 2.05 fλ/D, with a mean intensity 3.5×10^-8. We discuss the contributions to this floor, and the techniques being developed to improve it. We also present simulations that investigate the effect of Lyot stops of various sizes, and conclude that a Lyot stop is necessary for 10^-9 performance but that an annular postapodizer is not necessary.

Proceedings Article | 15 September 2011

Studies of the effects of optical system errors on the HCIT contrast performance

Erkin Sidick, Stuart Shaklan, Amir Give'on, Brian Kern

Proceedings Volume 8151, 815106 (2011) https://doi.org/10.1117/12.894453

KEYWORDS: Actuators, Error analysis, Wavefronts, Coronagraphy, Process control, Planets, Optical components, Optical simulations, Computer simulations, Cesium

Read Abstract +

The High Contrast Imaging Testbed (HCIT) at the Jet Propulsion Laboratory employs a broadband wavefront correction algorithm called Electric Field Conjugation (EFC) to obtain the required 10^-10 contrast. This algorithm works with one deformable mirror (DM) to estimate the electric-field to be controlled, and with one or multiple DM's to create a "darkhole" in a predefined region of the image plane where terrestrial planets would be found. We have investigated the effects of DM actuator errors and the optic position errors on the efficiency of the EFC algorithm in a Lyot coronagraph configuration. The structural design of the optical system as well as the parameters of various optical elements used in the analysis are drawn from those of the HCIT system that have been implemented with one DM. The simulation takes into account the surface errors of various optical elements. Results of some of these studies have been verified by actual measurements.

Proceedings Article | 15 September 2011

Phase-Induced Amplitude Apodization (PIAA) coronagraphy: recent results and future prospects

Olivier Guyon, Brian Kern, Ruslan Belikov, Stuart Shaklan, Andreas Kuhnert, Amir Give'on

Proceedings Volume 8151, 81510H (2011) https://doi.org/10.1117/12.894314

KEYWORDS: Coronagraphy, Apodization, Telescopes, Space telescopes, Control systems, Aspheric optics, Exoplanets, Manufacturing, Wavefronts, Optics manufacturing

Read Abstract +

The Phase Induced Amplitude Apodization (PIAA) concept uses aspheric optics to apodize a telescope beam for high contrast imaging. The lossless apodization, achieved through geometrical redistribution of the light (beam shaping) allows designs of high performance coronagraphs, ideally suited for direct imaging of exoplanets similar to Earth around nearby stars. The PIAA coronagraph concept has evolved since its original formulation to mitigate manufacturing challenges and improve performance. Our group is currently aiming at demonstrating PIAA coronagraphy in the laboratory to 1e-9 raw contrast at 2 λ/D separation. Recent results from the High Contrast Imaging Testbed (HCIT) at NASA JPL and the PIAA testbed at NASA Ames demonstrate contrasts about one order of magnitude from this goal at 2 λ/D. In parallel with our high contrast demonstration at 2λ/D, we are developing and testing new designs at a complementary testbed at NASA Ames, and solving associated technical challenges. Some of these new PIAA designs have been tested that can further mitigate PIAA manufacturing challenges while providing theoretically total starlight extinction and offering 50% throughput at less than 1 λ/D. Recent tests demonstrated on the order of 1e-6 contrast close to 1 λ/D (while maintaining 5e-8 contrast at 2 λ/D).

Proceedings Article | 15 September 2011

Recent progress in vector vortex coronagraphy

E. Serabyn, D. Mawet, J. Wallace, K. Liewer, J. Trauger, D. Moody, B. Kern

Proceedings Volume 8146, 81460L (2011) https://doi.org/10.1117/12.895267

KEYWORDS: Coronagraphy, Spiral phase plates, Space telescopes, Exoplanets, Telescopes, Optical vortices, Wavefronts, Phase measurement, Polarization, Speckle

Read Abstract +

The optical vortex coronagraph has great potential for enabling high-contrast observations very close to bright stars, and thus for reducing the size of space telescopes needed for exoplanet characterization missions. Here we discuss several recent developments in optical vortex coronagraphy. In particular, we describe multi-stage vortex configurations that allow the use of on-axis telescopes for high-contrast coronagraphy, and also enable the direct measurement of the amplitudes and phases of focal plane speckles. We also briefly describe recent laboratory demonstrations of the optical properties of the dual-stage vortex, and of the broadband performance of single stage vortex masks. Indeed, the demonstrated performance of the vector vortex phase masks already in hand, ≈ 10^-8, is approximately that needed for an initial coronagraphic mission, such as an exoplanet explorer, aimed at detecting exozodiacal light and jovian exoplanets.

Proceedings Article | 11 August 2010

Studies of the effects of actuator errors on the HCIT/PIAA contrast performance

Erkin Sidick, Stuart Shaklan, Brian Kern, Amir Give'on

Proceedings Volume 7731, 77314T (2010) https://doi.org/10.1117/12.858050

KEYWORDS: Actuators, Apodization, Wavefronts, Point spread functions, Optical components, Imaging systems, Coronagraphy, Mirrors, Control systems, Curium

Read Abstract +

The High Contrast Imaging Testbed Phase Induced Amplitude Apodization (HCIT/PIAA) coronagraph system at JPL relies on an Electric-Field Conjugation (EFC) wavefront correction algorithm to create a high contrast point-spread function (PSF). This algorithm works with one deformable mirror (DM) to estimate the electric-field to be controlled, and with one or multiple DM's to create a "dark-hole" in the image plane. We have investigated the effects of DM actuator errors on the efficiency of the EFC algorithm. The structural design of the optical system as well as the parameters of various optical elements used in the analysis are drawn from those of the HCIT/PIAA system that have been and will be implemented with one or two DM's. The simulation takes into account the surface errors of various optical elements. In this paper, we report our findings in the case of narrowband wavelength light.

Proceedings Article | 6 August 2010

The pupil mapping exoplanet coronagraphic observer (PECO)

Olivier Guyon, Stuart Shaklan, Marie Levine, Kerri Cahoy, Domenick Tenerelli, Ruslan Belikov, Brian Kern

Proceedings Volume 7731, 773129 (2010) https://doi.org/10.1117/12.857918

KEYWORDS: Coronagraphy, Exoplanets, Imaging spectroscopy, Space telescopes, Infrared telescopes, Telescopes, Spectroscopy, Planets, Infrared radiation, Extremely high frequency

Read Abstract +

The Pupil-mapping Exoplanet Coronagraphic Observer (PECO) mission concept is a 1.4-m space-based coronagraphic telescope optimized to image exoplanets and disks at optical wavelengths and characterize them through low resolution spectroscopy and polarimetry. Thanks to a high efficiency Phase-Induced Amplitude Apodization (PIAA) coronagraph, PECO can deliver 1e-10 contrast at 2 λ/D separation (0.15") with no loss in angular resolution or throughput due to the coronagraph. PECO acquires narrow field images simultaneously in 16 spectral bands over wavelengths from 0.4 to 0.9 μm , utilizing all available photons for maximum wavefront sensing efficiency and optimal sensitivity for imaging and spectroscopy. PECO can detect and characterize potentially habitable planets around 20 known F, G, K type stars, and map exozodiacal clouds to a fraction of our own own zodiacal dust content. PECO's key technologies are currently under active development at several testbeds, and will enable efficient exoplanet imaging missions across a wide range of telescope sizes, from a sub-meter debris disk and giant planet imager to a ~4-m life-finding mission.

Proceedings Article | 20 August 2009

Phase-induced amplitude apodization (PIAA) coronagraph testing at the High Contrast Imaging Testbed

Brian Kern, Ruslan Belikov, Amir Give'on, Olivier Guyon, Andreas Kuhnert, Marie Levine-West, Ian McMichael, Dwight Moody, Albert Niessner, Laurent Pueyo, Stuart Shaklan, Wesley Traub, John Trauger

Proceedings Volume 7440, 74400H (2009) https://doi.org/10.1117/12.826988

KEYWORDS: Wavefronts, Coronagraphy, Mirrors, Apodization, Cameras, Planets, Point spread functions, Computer generated holography, Actuators, Data modeling

Read Abstract +

We present the current status of our testing of a phase-induced amplitude apodization (PIAA) coronagraph at the Jet Propulsion Lab's High Contrast Imaging Testbed (HCIT) vacuum facilities. These PIAA optics were designed to produce a point-spread function containing a region whose intensity is below 10^-9 over a 20-percent fractional bandpass, comparable to the requirements for direct imaging of exoplanets from space. The results presented here show contrast levels of 4×10^-7 in monochromatic light, with an inner working angle of 2.4 λ/D. The instrumentation is described here, as well as the testing procedures, wavefront control, and results.

Proceedings Article | 20 August 2009

Detecting and characterizing exoplanets with a 1.4-m space telescope: the Pupil mapping Exoplanet Coronagraphic Observer (PECO)

Olivier Guyon, James R. Angel, Ruslan Belikov, Robert Egerman, Donald Gavel, Amir Give'on, Thomas Greene, Kerri Cahoy, Brian Kern, Marie Levine, Stephen Ridgway, Stuart Shaklan, Domenick Tenerelli, Robert Vanderbei, Robert Woodruff

Proceedings Volume 7440, 74400F (2009) https://doi.org/10.1117/12.826350

KEYWORDS: Coronagraphy, Space telescopes, Telescopes, Wavefronts, Exoplanets, Planets, Mirrors, Stars, Apodization, Optical design

Read Abstract +

The Pupil-mapping Exoplanet Coronagraphic Observer (PECO) mission concept uses a coronagraphic 1.4-m space-based telescope to both image and characterize extra-solar planetary systems at optical wavelengths. PECO delivers 10^-10 contrast at 2 λ/D separation (0.15") using a high-performance Phase-Induced Amplitude Apodization (PIAA) coronagraph which remaps the telescope pupil and uses nearly all of the light coming into the aperture. For exoplanet characterization, PECO acquires narrow field images simultaneously in 16 spectral bands over wavelengths from 0.4 to 0.9 μm, utilizing all available photons for maximum wavefront sensing and sensitivity for imaging and spectroscopy. The optical design is optimized for simultaneous low-resolution spectral characterization of both planets and dust disks using a moderate-sized telescope. PECO will image the habitable zones of about 20 known F, G, K stars at a spectral resolution of R≈15 with sensitivity sufficient to detect and characterize Earth-like planets and to map dust disks to within a fraction of our own zodiacal dust cloud brightness. The PIAA coronagraph adopted for PECO reduces the required telescope diameter by a factor of two compared with other coronagraph approaches that were considered for Terrestrial Planet Finder Coronagraph Flight Baseline 1, and would therefore also be highly valuable for larger telescope diameters. We report on ongoing laboratory activities to develop and mature key PECO technologies, as well as detailed analysis aimed at verifying PECO's wavefront and pointing stability requirement can be met without requiring development of new technologies.

Proceedings Article | 14 July 2008

Planetscope: an exoplanet coronagraph on a balloon platform

Wesley Traub, Pin Chen, Brian Kern, Taro Matsuo

Proceedings Volume 7010, 70103S (2008) https://doi.org/10.1117/12.788087

KEYWORDS: Coronagraphy, Wavefronts, Exoplanets, Turbulence, Lithium, Point spread functions, Interferometers, Telescopes, Wavefront aberrations, Personal protective equipment

Read Abstract +

Direct detection of mature exoplanets is possible using a visible-wavelength telescope and coronagraph in the stratosphere. We analyze two sources of dynamic wavefront perturbations: turbulence in the free atmosphere and locally generated turbulence. We find that they are expected to have relatively small effects on the wavefront. We find that neither source should limit observations at 10^-9 contrast levels for planet-star separations of 0.5 arcsec. On this basis, we expect that it is feasible to image and characterize several known radial-velocity exoplanets.

Proceedings Article | 19 September 2007

Thickness-dependent optical properties of metals and alloys applicable to TPF coronagraph image masks

Kunjithapatham Balasubramanian, Daniel Wilson, Richard Muller, Brian Kern, Erkin Sidick

Proceedings Volume 6693, 66930Z (2007) https://doi.org/10.1117/12.732721

KEYWORDS: Nickel, Platinum, Phase measurement, Metals, Coronagraphy, Thin films, Optical properties, Chromium, Refractive index, Dielectrics

Read Abstract +

Some common metals and alloys have been identified as potential candidates with optical properties applicable to image plane masks for terrestrial planet finder (TPF) coronagraph especially for broad band performance in the visible spectrum. Thin films of these materials exhibit thickness dependence of refractive index and extinction coefficient which vary with wavelength and consequently the intensity and phase of transmitted light. We report on the fabrication and measurement of thickness-dependent optical properties of thin films of Ni, Pt and Inconel alloys to enable optimum design of image plane masks for Lyot coronagraphs to operate in the 500 to 800 nm band. We discuss the potential and limitations of practical masks with such materials.

Proceedings Article | 19 September 2007

Optimizing the broadband performance of TPF's high-contrast imaging testbed through modeling and simulations

Erkin Sidick, Brian Kern, Anreas Kuhnert

Proceedings Volume 6693, 66931B (2007) https://doi.org/10.1117/12.731676

KEYWORDS: Actuators, Glasses, Modeling and simulation, Algorithm development, Coronagraphy, Curium, Speckle, Optical simulations, Microscopes, Yield improvement

Read Abstract +

We have carried out some investigation to optimize the broadband performance of the high-contrast imaging testbed (HCIT) at JPL through optical modeling and simulations. The analytical tool is an optical simulation algorithm developed by combining the HCIT's optical model with a speckle-nulling algorithm that operates directly on coronagraphic images, an algorithm very similar to the one that has been used on the HCIT. We have experimented in our simulations with different designs for the occulting mask and the Lyot Stop, and also tried several different speckle-nulling approaches. Some results predicted by our simulations agree well with the results measured on the HCIT. In this paper we describe the details of our simulations and present our results.

Proceedings Article | 19 September 2007

Demonstration of high contrast in 10% broadband light with the shaped pupil coronagraph

Ruslan Belikov, Amir Give'on, Brian Kern, Eric Cady, Michael Carr, Stuart Shaklan, Kunjithapatham Balasubramanian, Victor White, Pierre Echternach, Matt Dickie, John Trauger, Andreas Kuhnert, N. Jeremy Kasdin

Proceedings Volume 6693, 66930Y (2007) https://doi.org/10.1117/12.734976

KEYWORDS: Wavefronts, Coronagraphy, Manufacturing, Speckle, Photomasks, Point spread functions, Control systems, Planets, Optics manufacturing, Imaging systems

Read Abstract +

The Shaped Pupil Coronagraph (SPC) is a high-contrast imaging system pioneered at Princeton for detection of extra-solar earthlike planets. It is designed to achieve 10^-10 contrast at an inner working angle of 4λ/D in broadband light. A critical requirement in attaining this contrast level in practice is the ability to control wavefront phase and amplitude aberrations to at least λ/10⁴ in rms phase and 1/1000 rms amplitude, respectively. Furthermore, this has to be maintained over a large spectral band. The High Contrast Imaging Testbed (HCIT) at the Jet Propulsion Lab (JPL) is a state-of-the-art facility for studying such high contrast imaging systems and wavefront control methods. It consists of a vacuum chamber containing a configurable coronagraph setup with a Xinetics deformable mirror. Previously, we demonstrated 4x10^-8 contrast with the SPC at HCIT in 10% broadband light. The limiting factors were subsequently identified as (1) manufacturing defects due to minimal feature size constraints on our shaped pupil masks and (2) the inefficiency of the wavefront correction algorithm we used (classical speckle nulling) to correct for these defects. In this paper, we demonstrate the solutions to both of these problems. In particular, we present a method to design masks with practical minimal feature sizes and show new manufactured masks with few defects. These masks were installed at HCIT and tested using more sophisticated wavefront control algorithms based on energy minimization of light in the dark zone. We present the results of these experiments, notably a record 2.4×10^-9 contrast in 10% broadband light.

Proceedings Article | 19 September 2007

Wavelength-dependent complex transmission profiles of band-limited coronagraph occulting masks measured in situ

Brian Kern, Daniel Wilson

Proceedings Volume 6693, 66931F (2007) https://doi.org/10.1117/12.733949

KEYWORDS: Calibration, Coronagraphy, Solids, Light scattering, Glasses, Convolution, Phase measurement, Absorption, Microscopes, Fourier transforms

Read Abstract +

Practical band-limited occulting masks used in visible-light Lyot coronagraphs, such as those proposed for the Terrestrial Planet Finder Coronagraph (TPF-C), will exhibit some non-band-limited transmission errors that may limit their observing contrast ratios to unacceptable levels. The complex (both phase and amplitude) transmission profiles of these masks exhibit large dynamic ranges over small spatial scales, which are difficult to probe using ordinary optical microscopes and interferometers. We describe here a technique for making these complex transmission measurements with the mask in-place in a Lyot coronagraph, using point-source images taken in the focal and pupil planes, with the Lyot stop removed. We also present measurements taken from the High-Contrast Imaging Testbed (HCIT) at JPL.

Proceedings Article | 19 September 2007

Laboratory demonstrations of high-contrast imaging for space coronagraphy

John Trauger, Amir Give'on, Brian Gordon, Brian Kern, Andreas Kuhnert, Dwight Moody, Albert Niessner, Fang Shi, Daniel Wilson, Chris Burrows

Proceedings Volume 6693, 66930X (2007) https://doi.org/10.1117/12.735004

KEYWORDS: Coronagraphy, Stars, Wavefronts, Deformable mirrors, Speckle, Actuators, Mirrors, Signal attenuation, Space telescopes, Imaging systems

Read Abstract +

Space coronagraphy is a promising method for direct imaging of planetary systems orbiting the nearby stars. The High Contrast Imaging Testbed is a laboratory facility at JPL that integrates the essential hardware and control algorithms needed for suppression of diffracted and scattered light near a target star that would otherwise obscure an associated exo-planetary system. Stable suppression of starlight by a factor of 5×10⁻¹⁰ has been demonstrated consistently in narrowband light over fields of view as close as four Airy radii from the star. Recent progress includes the extension of spectral bandwidths to 10% at contrast levels of 2×10⁻⁹, with work in progress to further improve contrast levels, bandwidth, and instrument throughput. We summarize recent laboratory results and outline future directions. This laboratory experience is used to refine computational models, leading to performance and tolerance predictions for future space mission architectures.

Proceedings Article | 18 September 2007

Broadband wavefront correction algorithm for high-contrast imaging systems

Amir Give'on, Brian Kern, Stuart Shaklan, Dwight Moody, Laurent Pueyo

Proceedings Volume 6691, 66910A (2007) https://doi.org/10.1117/12.733122

KEYWORDS: Actuators, Wavefronts, Reconstruction algorithms, Coronagraphy, Imaging systems, Image filtering, Planets, Control systems, Spatial frequencies, Deformable mirrors

Read Abstract +

Great strides have been made in recent years toward the goal of high-contrast imaging with a sensitivity adequate to detect earth-like planets around nearby stars. It appears that the hardware − optics, coronagraph masks, deformable mirrors, illumination systems, thermal control systems − are up to the task of obtaining the required 10^-10 contrast. But in broadband light (e.g., 10% bandpass) the wavefront control algorithms have been a limiting factor. In this paper we describe a general correction methodology that works in broadband light with one or multiple deformable mirrors by conjugating the electric field in a predefined region in the image where terrestrial planets would be found. We describe the linearized approach and demonstrate its effectiveness through laboratory experiments. This paper presents results from the Jet Propulsion Laboratory High Contrast Imaging Testbed (HCIT) for both narrow-band light (2%) and broadband light (10%) correction.

Proceedings Article | 7 July 2006

The effects of instrumental elliptical polarization on stellar point spread function fine structure

Joseph Carson, Brian Kern, John Trauger, James Breckinridge

Proceedings Volume 6265, 62653M (2006) https://doi.org/10.1117/12.672518

KEYWORDS: Point spread functions, Mirrors, Polarization, Reflectivity, Coating, Reflection, Space telescopes, Elliptical polarization, Numerical analysis, Spherical lenses

Read Abstract +

We present a status report on a study on the effects of instrumental polarization on the fine structure of the stellar point spread function (PSF). These effects are important to understand because the the aberration caused by instrumental polarization on an otherwise diffraction-limited PSF will likely have have severe consequences for extreme high contrast imaging systems such as NASA's proposed Terrestrial Planet Finder (TPF) mission and the proposed NASA Eclipse mission. The report here, describing our efforts to examine these effects, includes two parts: 1) a numerical analysis of the effect of metallic reflection, with some polarization-specific retardation, on a spherical wavefront; 2) an experimental approach for observing this effect, along with a status report on preliminary laboratory results. The numerical analysis indicates that the inclusion of polarization-specific phase effects (retardation) results in a point spread function (PSF) aberration more severe than the amplitude (reflectivity) effects previously recorded in the literature. Preliminary in-lab results are consistent with our numerical predictions.

DOWNLOAD PAPER

Proceedings Article | 14 June 2006

Speckle nulling for exoplanet detection with space-based coronagraphic telescopes

Pascal Bordé, Wesley Traub, Brian Kern, John Trauger, Andreas Kuhnert

Proceedings Volume 6265, 62651C (2006) https://doi.org/10.1117/12.670553

KEYWORDS: Speckle, Coronagraphy, Actuators, Planets, Space telescopes, Telescopes, Stars, Sensors, Deformable mirrors, Exoplanetary science

Read Abstract +

To detect Earth-like planets in the visible with a coronagraphic telescope, two major noise sources have to be overcome: the photon noise of the diffracted star light, and the speckle noise due to the star light scattered by instrumental defects. Coronagraphs tackle only the photon noise contribution. In order to decrease the speckle noise below the planet level, an active control of the wave front is required. We have developed analytical methods to measure and correct the speckle noise behind a coronagraph with a deformable mirror. In this paper, we summarize these methods, present numerical simulations, and discuss preliminary experimental results obtained with the High-Contrast Imaging Testbed at NASA's Jet Propulsion Laboratory.

My Library

You currently do not have any folders to save your paper to! Create a new folder below.

Folder Name

Folder Description

Showing 5 of 84 publications

LOAD MORE

SIGN IN TO:

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Advertisement

Advertisement

Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks. You are receiving this notice because your organization may not have SPIE eBooks access.*

*Shibboleth/Open Athens users─please sign in to access your institution's subscriptions.

To obtain this item, you may purchase the complete book in print or electronic format on SPIE.org.

ORGANIZATIONAL
Sign in with credentials provided by your organization.

Organizational Username

Organizational Password
Show/Hide Password

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members:

Non-members: ADD TO CART

Keywords/Phrases

Search In:

Publication Years