Dr. Alexander D. Hedglen Profile

Dr. Alexander D. Hedglen

SPIE Involvement:

Author

Publications (24)

Proceedings Article | 6 October 2023 Presentation

Presentation

MagAO-X: a pathfinder for GMT to operate extreme adaptive optics at the photon noise limit

Sebastiaan Haffert, Jared Males, Laird Close, Olivier Guyon, Joseph Long, Alexander Hedglen, Maggie Kautz, Kyle Van Gorkom, Avalon McLeod, Warren Foster, Eden McEwen, Logan Pearce, Jialin Li, Jay Kueny, Ben Mazin, Noah Swimmer, Jeb Bailey, Sarah Steiger

Proceedings Volume 12680, 1268008 (2023) https://doi.org/10.1117/12.2677533

KEYWORDS: Coronagraphy, Adaptive optics, Planets, Equipment, Reflection, Imaging systems, Wavefront sensors, Telescopes, Stars, Exoplanetary science

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Proceedings Article | 3 October 2022 Open Access

Open Access

Paper

The practical optics workshop: educating the optical engineers of tomorrow

Jaren N. Ashcraft, Trenton Brendel, Simran Agarwal, Joel Berkson, Alexander Hedglen, Hyukmo Kang, Yanqi Zhang, Heejoo Choi, Daewook Kim

Proceedings Volume 12213, 122130H (2022) https://doi.org/10.1117/12.2632801

KEYWORDS: Optics education, Education and training, Optical design, Optical engineering, Optical design software

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Proceedings Article | 30 August 2022 Presentation + Paper

Presentation + Paper

MagAO-X: current status and plans for Phase II

Jared Males, Laird Close, Sebastiaan Haffert, Joseph Long, Alexander Hedglen, Logan Pearce, Alycia Weinberger, Olivier Guyon, Justin Knight, Avalon McLeod, Maggie Kautz, Kyle Van Gorkom, Jennifer Lumbres, Lauren Schatz, Alex Rodack, Victor Gasho, Jay Kueny, Warren Foster

Proceedings Volume 12185, 1218509 (2022) https://doi.org/10.1117/12.2630584

KEYWORDS: Coronagraphy, Adaptive optics, Telescopes, Algorithm development, Actuators, Imaging systems, Wavefront sensors, Planets, Stars

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Proceedings Article | 30 August 2022 Poster + Paper

Poster + Paper

A novel hexpyramid pupil slicer for an ExAO parallel DM for the Giant Magellan Telescope

Maggie Kautz, Laird Close, Alex Hedglen, Sebastiaan Haffert, Jared Males, Fernando Coronado

Proceedings Volume 12185, 121854G (2022) https://doi.org/10.1117/12.2629733

KEYWORDS: Mirrors, Actuators, Computer aided design, Telescopes, Wavefronts, Point spread functions, Optical design, Deformable mirrors, Polarization, Image segmentation

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Proceedings Article | 30 August 2022 Poster + Paper

Poster + Paper

Advanced wavefront sensing and control demonstration with MagAO-X

Sebastiaan Haffert, Jared Males, Kyle Van Gorkom, Laird Close, Joseph Long, Alexander Hedglen, Kyohoon Ahn, Olivier Guyon, Lauren Schatz, Maggie Kautz, Jennifer Lumbres, Alexander Rodack, Justin Knight, He Sun, Kevin Fogarty, Kelsey Miller

Proceedings Volume 12185, 1218581 (2022) https://doi.org/10.1117/12.2630425

KEYWORDS: Wavefront sensors, Planets, Adaptive optics, Coronagraphy, Exoplanets, Autoregressive models

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Proceedings Article | 30 August 2022 Presentation + Paper

Presentation + Paper

Phasing the segmented Giant Magellan Telescope: progress in testbeds and prototypes

Richard Demers, Antonin Bouchez, Fernando Quiros-Pacheco, Patricio Schurter, Breann Sitarski, Marcos van Dam, Dan Catropa, Jan Kansky, Brian McLeod, Stuart McMuldroch, Bill Podgorski, Laird Close, Victor Gasho, Sebastiaan Haffert, Alex Hedglen, Maggie Kautz, Jared Males, Guido Agapito, Nicolò Azzaroli, Luca Carbonaro, Anne-Laure Cheffot, Simone Esposito, Tommaso Lapucci, Enrico Pinna, Cédric Plantet, Alfio Puglisi, Fabio Rossi, Guillermo Gonzalez, Bijan Nemati

Proceedings Volume 12185, 1218518 (2022) https://doi.org/10.1117/12.2630144

KEYWORDS: Prototyping, Wavefronts, Wavefront sensors, Telescopes, Sensors, Image segmentation, Adaptive optics, Device simulation, Stars, Cameras

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Proceedings Article | 30 August 2022 Presentation + Paper

Presentation + Paper

The optical and mechanical design for the 21,000 actuator ExAO system for the Giant Magellan Telescope: GMagAO-X

Laird Close, Jared Males, Olivier Durney, Fernando Coronado, Sebastiaan Haffert, Victor Gasho, Alexander Hedglen, Maggie Kautz, Tom Connors, Mark Sullivan, Olivier Guyon, Jamison Noenickx

Proceedings Volume 12185, 1218524 (2022) https://doi.org/10.1117/12.2629553

KEYWORDS: Actuators, Telescopes, Mechanical engineering, Planets, Optomechanical design, Coronagraphy, Optical design, Optical benches, Polarization, Mirrors

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Proceedings Article | 30 August 2022 Presentation + Paper

Presentation + Paper

First lab results of segment/petal phasing with a pyramid wavefront sensor and a novel holographic dispersed fringe sensor (HDFS) from the Giant Magellan Telescope high contrast adaptive optics phasing testbed

Alexander Hedglen, Laird Close, Sebastiaan Haffert, Jared Males, Maggie Kautz, Antonin Bouchez, Richard Demers, Fernando Quirós-Pacheco, Breann Sitarski, Olivier Guyon, Kyle Van Gorkom, Joseph Long, Jennifer Lumbres, Lauren Schatz, Kelsey Miller, Alex Rodack, Justin Knight

Proceedings Volume 12185, 1218516 (2022) https://doi.org/10.1117/12.2629538

KEYWORDS: Sensors, Adaptive optics, Point spread functions, Image segmentation, Modulation, Turbulence, Mirrors, Coronagraphy, Wavefront sensors, Telescopes

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The Giant Magellan Telescope (GMT) design consists of seven circular 8.4-m diameter mirror segments that are separated by large > 30 cm gaps, making them susceptible to fluctuations in optical path differences (piston) due to flexure, segment vibrations, wind buffeting, temperature effects, and atmospheric seeing. If we wish to utilize the full 25.4-m diffractionlimited aperture of the GMT for high-contrast natural guide star adaptive optics (NGSAO) science (e.g., direct imaging of habitable zone earth-like planets around late type stars), the seven mirror segments must be co-phased to well within a fraction of a wavelength. The current design of the GMT involves seven adaptive secondary mirrors, a dispersed fringe sensor, and a pyramid wavefront sensor (PyWFS) to measure and correct the total path length between segment pairs, but these methods need to be tested “end-to-end” in a lab environment if we hope to officially retire the GMT high risk item of phasing performance. We present the design and working prototype of a “GMT High-Contrast Adaptive Optics phasing Testbed” (p-HCAT) which leverages the existing MagAO-X ExAO instrument to demonstrate segment phase sensing and simultaneous AO-control for high-contrast GMT NGSAO science. We present the first test results of closed-loop piston control with one GMT segment using MagAO-X’s PyWFS and a novel Holographic Dispersed Fringe Sensor (HDFS) with and without simulated atmospheric turbulence. We show that the PyWFS alone was able to successfully control piston without turbulence within 12-33 nm RMS for 0 λ/D – 5 λ/D modulation, but was unsuccessful at controlling segmented piston with generated ∼ 0.6 arcsec and ∼ 1.2 arcsec seeing turbulence due to non-linear modal cross-talk and poor pixel sampling of the segment gaps on the PyWFS detector. We report the success of an alternate solution to control segmented piston using the novel HDFS while controlling all other modes with the PyWFS purely as a slope sensor (piston mode removed). This “second channel” WFS method worked well to control piston to within 50 nm RMS and ± 10 μm dynamic range under simulated 0.6 arcsec and 1.2 arcsec atmospheric seeing conditions. These results suggest that a PyWFS alone is not an ideal piston sensor for the GMT and likely other Giant Segmented Mirror Telescopes (GSMTs) as well. Therefore, an additional “second channel” piston sensor, such as the novel HDFS, is strongly suggested.

Proceedings Article | 30 August 2022 Paper

Paper

The conceptual design of GMagAO-X: visible wavelength high contrast imaging with GMT

Jared Males, Laird Close, Sebastiaan Haffert, Olivier Guyon, Victor Gasho, Fernando Coronado, Oliver Durney, Alexander Hedglen, Maggie Kautz, Jamison Noenickx, John Ford, Tom Connors, Doug Kelly

Proceedings Volume 12185, 121854J (2022) https://doi.org/10.1117/12.2630619

KEYWORDS: Planets, Exoplanets, Adaptive optics, Actuators, Stars, Coronagraphy, Telescopes, Control systems, Speckle, Performance modeling

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Proceedings Article | 30 August 2022 Poster + Paper

Poster + Paper

Visible extreme adaptive optics for GMagAO-X with the triple-stage AO architecture (TSAO)

Sebastiaan Haffert, Jared Males, Laird Close, Olivier Guyon, Alexander Hedglen, Maggie Kautz

Proceedings Volume 12185, 121853D (2022) https://doi.org/10.1117/12.2630222

KEYWORDS: Wavefront sensors, Adaptive optics, Planets, Coronagraphy, Exoplanets

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Proceedings Article | 30 August 2022 Poster + Paper

Poster + Paper

XPipeline: starlight subtraction at scale for MagAO-X

Joseph Long, Jared Males, Sebastiaan Haffert, Laird Close, Katie Morzinski, Kyle Van Gorkom, Jennifer Lumbres, Warren Foster, Alexander Hedglen, Maggie Kautz, Alex Rodack, Lauren Schatz, Kelsey Miller, David Doelman, Steven Bos, Matthew Kenworthy, Frans Snik, Gilles P. P. Otten

Proceedings Volume 12185, 121853P (2022) https://doi.org/10.1117/12.2628975

KEYWORDS: Adaptive optics, Control systems, Human-machine interfaces, Telescopes, Real-time computing, Observatories, Image processing, Deformable mirrors, Data acquisition, Wavefront sensors

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Proceedings Article | 29 August 2022 Poster

Poster

The cumulative effect of low-order aberrations in the MagAO-X science path

Richard Frazin, Alex Hedglen, Alex Rodack, Jared Males, Laird Close, Olivier Guyon

Proceedings Volume 12185, 121853E (2022) https://doi.org/10.1117/12.2629438

KEYWORDS: Coronagraphy, Telescopes, Refraction, Polarization, Diffraction

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SPIE Journal Paper | 24 June 2022

Lab tests of segment/petal phasing with a pyramid wavefront sensor and a holographic dispersed fringe sensor in turbulence with the Giant Magellan Telescope high contrast adaptive optics phasing testbed

Alexander Hedglen, Laird Close, Sebastiaan Haffert, Jared Males, Maggie Kautz, Antonin Bouchez, Richard Demers, Fernando Quirós-Pacheco, Breann Sitarski, Olivier Guyon, Kyle Van Gorkom, Joseph D. Long, Jennifer Lumbres, Lauren Schatz, Kelsey Miller, Alex Rodack, Justin M. Knight

JATIS, Vol. 8, Issue 02, 021515, (June 2022) https://doi.org/10.1117/12.10.1117/1.JATIS.8.2.021515

KEYWORDS: Mirrors, Sensors, Wavefront sensors, Point spread functions, Wavefronts, Adaptive optics, Lens design, Modulation, Image segmentation, Turbulence

Read Abstract +

The Giant Magellan Telescope (GMT) design consists of seven circular 8.4-m diameter mirrors, together forming a single 25.4-m diameter primary mirror. This large aperture and collecting area can help extreme adaptive optics (ExAO) systems such as GMT’s GMagAO-X achieve the small angular resolutions and contrasts required to image habitable zone earth-like planets around late type stars and possibly lead to the discovery of life outside of our solar system. However, the GMT primary mirror segments are separated by large >30 cm gaps, creating the possibility of fluctuations in optical path differences (piston) due to flexure, segment vibrations, wind buffeting, temperature effects, and atmospheric seeing. To utilize the full diffraction-limited aperture of the GMT for high-contrast, natural guide star-adaptive optics science, the seven mirror segments must be co-phased to well within a fraction of a wavelength. The current design of the GMT involves seven adaptive secondary mirrors, a slow (∼0.03 Hz) off-axis dispersed fringe sensor (part of the acquisition guiding and wavefront sensing system’s active optics off-axis guider), and a pyramid wavefront sensor [PyWFS; part of the natural guide star wavefront sensor (NGWS) adaptive optics] to measure and correct the total path length between segment pairs, but these methods have yet to be tested “end-to-end” in a lab environment. We present the design and working prototype of a “GMT high contrast adaptive optics phasing testbed” that leverages the existing MagAO-X ExAO instrument to demonstrate segment phase sensing and simultaneous AO-control for high-contrast GMT natural guide star science [i.e., testing the NGWS wavefront sensor (WFS) architecture]. We present the first test results of closed-loop piston control with one GMT segment using MagAO-X’s PyWFS with and without simulated atmospheric turbulence. We show that the PyWFS was able to successfully control segment piston without turbulence within 12- to 33-nm RMS for 0 λ / D to 5 λ / D modulation, but was unsuccessful at controlling segment piston with generated ∼0.6 arcsec (median seeing conditions at the GMT site) and ∼1.2 arcsec seeing turbulence due to nonlinear modal cross-talk and poor pixel sampling of the segment gaps on the PyWFS detector. These results suggest that a PyWFS alone is not an ideal piston sensor for the GMT (and likely the TMT and ELT). Hence, a dedicated “second channel” piston sensor is required. We report the success of an alternate solution to control piston using a holographic dispersed fringe sensor (HDFS) while controlling all other modes with the PyWFS purely as a slope sensor (piston mode removed). This “second channel” WFS method worked well to control segment piston to within 50 nm RMS and ±10 μm dynamic range under simulated 0.6 arcsec atmospheric seeing (median seeing conditions at the GMT site). These results led to the inclusion of the HDFS as the official second channel piston sensor for the GMT NGWS WFS. This HDFS + PyWFS architecture should also work well to control piston petal modes on the ELT and TMT telescopes.

SPIE Journal Paper | 22 June 2022

Phasing the Giant Magellan Telescope with the holographic dispersed fringe sensor

Sebastiaan Haffert, Laird Close, Alexander Hedglen, Jared Males, Maggie Kautz, Antonin Bouchez, Richard Demers, Fernando Quirós-Pacheco, Breann Sitarski, Kyle Van Gorkom, Joseph Long, Olivier Guyon, Lauren Schatz, Kelsey Miller, Jennifer Lumbres, Alex Rodack, Justin Knight

JATIS, Vol. 8, Issue 02, 021513, (June 2022) https://doi.org/10.1117/12.10.1117/1.JATIS.8.2.021513

KEYWORDS: Sensors, Telescopes, Holography, Diffraction gratings, Adaptive optics, Wavefront sensors, Holograms, Point spread functions, Image segmentation, Wavefronts

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Proceedings Article | 1 September 2021 Presentation + Paper

Presentation + Paper

Data-driven subspace predictive control: lab demonstration and future outlook

Sebastiaan Haffert, Jared Males, Laird Close, Kyle van Gorkom, Joseph Long, Alexander Hedglen, Lauren Schatz, Jennifer Lumbres, Alexander Rodack, Justin Knight, He Sun, Kevin Fogarty, Logan Pearce

Proceedings Volume 11823, 118231C (2021) https://doi.org/10.1117/12.2594910

KEYWORDS: Adaptive optics, Planets, Autoregressive models, Wavefront sensors, Adaptive control

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Proceedings Article | 1 September 2021 Presentation + Paper

Presentation + Paper

Data-driven subspace predictive control: lab demonstration and future outlook

Sebastiaan Haffert, Jared Males, Laird Close, Joseph Long, Lauren Schatz, Kyle van Gorkom, Alexander Hedglen, Jennifer Lumbres, Alexander Rodack, Olivier Guyon, Justin Knight, Maggie Kautz, Logan Pearce

Proceedings Volume 11823, 1182306 (2021) https://doi.org/10.1117/12.2594875

KEYWORDS: Adaptive optics, Telescopes, Spectrographs, Reconstruction algorithms, Planets, Autoregressive models, Wavefronts, Stars, Actuators, Wavefront sensors

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SPIE Journal Paper | 2 August 2021

Characterizing deformable mirrors for the MagAO-X instrument

Kyle Van Gorkom, Jared Males, Laird Close, Jennifer Lumbres, Alex Hedglen, Joseph Long, Sebastiaan Haffert, Olivier Guyon, Maggie Kautz, Lauren Schatz, Kelsey Miller, Alexander Rodack, Justin Knight, Katie Morzinski

JATIS, Vol. 7, Issue 03, 039001, (August 2021) https://doi.org/10.1117/12.10.1117/1.JATIS.7.3.039001

KEYWORDS: Actuators, Point spread functions, Deformable mirrors, Wavefronts, Cameras, Interferometers, Adaptive optics, Telescopes, Microelectromechanical systems, Coronagraphy

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SPIE Journal Paper | 6 April 2021

Data-driven subspace predictive control of adaptive optics for high-contrast imaging

Sebastiaan Haffert, Jared Males, Laird Close, Kyle Van Gorkom, Joseph Long, Alexander Hedglen, Olivier Guyon, Lauren Schatz, Maggie Kautz, Jennifer Lumbres, Alexander Rodack, Justin Knight, He Sun, Kevin Fogarty

JATIS, Vol. 7, Issue 02, 029001, (April 2021) https://doi.org/10.1117/12.10.1117/1.JATIS.7.2.029001

KEYWORDS: Adaptive optics, Point spread functions, Adaptive control, Autoregressive models, Device simulation, Wavefronts, Wavefront sensors, Data modeling, Actuators, Turbulence

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Proceedings Article | 13 December 2020 Presentation + Paper

Presentation + Paper

Prediction of the planet yield of the MaxProtoPlanetS high-contrast survey for H-alpha protoplanets with MagAO-X based on first light contrasts

Laird Close, Jared Males, Joseph Long, Kyle Van Gorkom, Alexander Hedglen, Maggie Kautz, Jennifer Lumbres, Sebastiaan Haffert, Katherine Follette, Kevin Wagner, Kelsey Miller, Daniel Apai, Ya-Lin Wu, Olivier Guyon, Lauren Schatz, Alex Rodack, David Doelman, Frans Snik, Justin Knight, Katie Morzinski, Victor Gasho, Christoph Keller, Logan Pearce, Alycia Weinberger, Laura Pérez, René Doyon

Proceedings Volume 11448, 114480U (2020) https://doi.org/10.1117/12.2561677

KEYWORDS: Imaging systems, Adaptive optics, Cameras, Actuators, Exoplanets, Planets, Hydrogen, Magnetism, Stars, Coronagraphy

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Proceedings Article | 13 December 2020 Presentation + Paper

Presentation + Paper

The Giant Magellan Telescope high contrast phasing testbed

Alexander Hedglen, Laird Close, Antonin Bouchez, Jared Males, Richard Demers, Maggie Kautz, Ritvik Basant, Makayla Parkinson, Victor Gasho, Fernando Quirós-Pacheco, Breann Sitarski

Proceedings Volume 11448, 114482X (2020) https://doi.org/10.1117/12.2559893

KEYWORDS: Mirrors, Telescopes, Image segmentation, Sensors, Wavefront sensors, Optical instrument design, Adaptive optics, Spatial resolution, Planets, Solar system

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Proceedings Article | 13 December 2020 Poster + Paper

Poster + Paper

MagAO-X first light

Jared Males, Laird Close, Olivier Guyon, Alexander Hedglen, Kyle Van Gorkom, Joseph Long, Maggie Kautz, Jennifer Lumbres, Lauren Schatz, Alexander Rodack, Kelsey Miller, David Doelman, Frans Snik, Steven Bos, Justin Knight, Katie Morzinski, Victor Gasho, Christoph Keller, Sebastiaan Haffert, Logan Pearce

Proceedings Volume 11448, 114484L (2020) https://doi.org/10.1117/12.2561682

KEYWORDS: Coronagraphy, Adaptive optics, Imaging systems, Liquid crystal on silicon, Wavefront sensors, Telescopes, Lanthanum, Observatories, Deformable mirrors, Microelectromechanical systems

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Proceedings Article | 19 July 2018 Paper

Paper

Optical and mechanical design of the extreme AO coronagraphic instrument MagAO-X

Laird Close, Jared Males, Olivier Durney, Corwynn Sauve, Maggie Kautz, Alex Hedglen, Lauren Schatz, Jennifer Lumbres, Kelsey Miller, Kyle Van Gorkom, Madison Jean, Victor Gasho

Proceedings Volume 10703, 107034Y (2018) https://doi.org/10.1117/12.2312280

KEYWORDS: Adaptive optics, Coronagraphy, Telescopes, Near infrared, Cameras, Optical benches, Mechanical engineering, Visible radiation, Point spread functions, Actuators

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Proceedings Article | 11 July 2018 Paper

Paper

Optical field/pupil rotator with a novel compact K-mirror for MagAO-X

Alexander Hedglen, Laird Close, Jared Males, Olivier Durney

Proceedings Volume 10703, 1070355 (2018) https://doi.org/10.1117/12.2312346

KEYWORDS: Mirrors, Telescopes, Adaptive optics, Prototyping, Coronagraphy, Glasses, Photovoltaics, Zemax, Adhesives, Diffusers

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Proceedings Article | 10 July 2018 Presentation + Paper

Presentation + Paper

MagAO-X: project status and first laboratory results

Jared Males, Laird Close, Kelsey Miller, Lauren Schatz, David Doelman, Jennifer Lumbres, Frans Snik, Alex Rodack, Justin Knight, Kyle Van Gorkom, Joseph Long, Alex Hedglen, Maggie Kautz, Nemanja Jovanovic, Katie Morzinski, Olivier Guyon, Ewan Douglas, Katherine Follette, Julien Lozi, Chris Bohlman, Olivier Durney, Victor Gasho, Phil Hinz, Michael Ireland, Madison Jean, Christoph Keller, Matt Kenworthy, Ben Mazin, Jamison Noenickx, Dan Alfred, Kevin Perez, Anna Sanchez, Corwynn Sauve, Alycia Weinberger, Al Conrad

Proceedings Volume 10703, 1070309 (2018) https://doi.org/10.1117/12.2312992

KEYWORDS: Coronagraphy, Stars, Telescopes, Adaptive optics, Planets, Wavefronts, Computing systems, Observatories

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Showing 5 of 24 publications

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