Dr. F. Ernesto Penado Profile

Dr. F. Ernesto Penado

Professor, Dept of Mechanical Engg at Northern Arizona Univ

SPIE Involvement:

Author

Publications (21)

Proceedings Article | 20 August 2020 Presentation + Paper

An approach to upgrading the beam transport system at the Navy Precision Optical Interferometer

James Clark, F. Ernesto Penado, Sergio Restaino, Henrique Schmitt

Proceedings Volume 11488, 1148804 (2020) https://doi.org/10.1117/12.2567933

KEYWORDS: Mirrors, Wavefronts, Telescopes, Interferometers, Relays, Precision optics, Imaging systems, Light emitting diodes

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Proceedings Article | 30 August 2019 Presentation + Paper

Optomechanical design considerations for a vacuum window for optical and infrared interferometry

F. Ernesto Penado, James Clark

Proceedings Volume 11100, 1110002 (2019) https://doi.org/10.1117/12.2528204

KEYWORDS: Glasses, Metals, Infrared radiation, Interferometers, Interferometry, Finite element methods, Optomechanical design, Failure analysis

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Proceedings Article | 19 September 2018 Presentation + Paper

Experimental verification of compliant mirror wavefront correction using a single actuator

James Clark III, F. Ernesto Penado, Micha Heilman, Wyatt Clark

Proceedings Volume 10747, 1074708 (2018) https://doi.org/10.1117/12.2320701

KEYWORDS: Mirrors, Wavefronts, Actuators, Interferometers, Deformable mirrors, Observatories, Finite element methods, Relays, Phase shifts, Precision optics, Long baseline optical interferometry

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SPIE Journal Paper | 28 April 2016

Compliant deformable mirror approach for wavefront improvement

James Clark, F. Ernesto Penado

OE, Vol. 55, Issue 04, 043107, (April 2016) https://doi.org/10.1117/12.10.1117/1.OE.55.4.043107

KEYWORDS: Mirrors, Wavefronts, Deformable mirrors, Actuators, Relays, Interferometers, Adaptive optics, Finite element methods, Calibration, Wavefront distortions

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Proceedings Article | 2 September 2015 Paper

Elliptically framed tip-tilt mirror optimized for stellar tracking

James Clark, F. Penado, Jeremy Petak

Proceedings Volume 9573, 95730B (2015) https://doi.org/10.1117/12.2187559

KEYWORDS: Mirrors, Aluminum, Computer aided design, Actuators, Optical tracking, Telescopes, Solid modeling, Space telescopes, Glasses, Precision optics

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Proceedings Article | 8 September 2014 Paper

Analysis methodology for a piezoelectric-driven optical tracker for ground-based interferometry

James Clark, F. Ernesto Penado

Proceedings Volume 9195, 91950A (2014) https://doi.org/10.1117/12.2062490

KEYWORDS: Actuators, Mirrors, Optical tracking, Telescopes, Ferroelectric materials, Relays, Interferometers, Ocean optics, Interferometry, Analytical research

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SPIE Journal Paper | 9 January 2014 Open Access

Method of analysis for determining and correcting mirror deformation due to gravity

James Clark, F. Ernesto Penado

OE, Vol. 53, Issue 01, 015102, (January 2014) https://doi.org/10.1117/12.10.1117/1.OE.53.1.015102

KEYWORDS: Mirrors, Off axis mirrors, Adaptive optics, Finite element methods, Interferometers, Wavefronts, Analytical research, Optical engineering, Chemical elements, Precision optics

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Proceedings Article | 15 October 2012 Paper

A support structure for a compliant deformable mirror

F. Ernesto Penado, James Clark, Joel Dugdale

Proceedings Volume 8491, 84910D (2012) https://doi.org/10.1117/12.930008

KEYWORDS: Mirrors, Wavefronts, Actuators, Relays, Deformable mirrors, Reflectivity, Finite element methods, Adaptive optics, Interferometers, Reflection

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Proceedings Article | 24 September 2011 Paper

Deformation analysis of tilted primary mirror for an off-axis beam compressor

James Clark, F. Ernesto Penado, Joel Dugdale

Proceedings Volume 8125, 81250C (2011) https://doi.org/10.1117/12.894167

KEYWORDS: Mirrors, Off axis mirrors, Wavefronts, Relays, Interferometers, Finite element methods, Adaptive optics, Observatories, Prototyping, Wavefront aberrations

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Proceedings Article | 10 September 2011 Paper

Analysis of a compliant static deformable mirror for wavefront error cancellation

F. Ernesto Penado, James Clark, Joel Dugdale

Proceedings Volume 8127, 81270C (2011) https://doi.org/10.1117/12.894168

KEYWORDS: Mirrors, Wavefronts, Relays, Adaptive optics, Actuators, Wavefront distortions, Interferometers, Deformable mirrors, Error analysis, Finite element methods

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Proceedings Article | 3 September 2010 Paper

Stiffening an off-axis beam compressor mount for improved performance

F. Ernesto Penado, James Clark, Frank Cornelius

Proceedings Volume 7793, 77930G (2010) https://doi.org/10.1117/12.860270

KEYWORDS: Mirrors, Prototyping, Aluminum, Interferometers, Finite element methods, Observatories, Mirror mounts, Relays, Analytical research, Visible radiation

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The Navy Prototype Optical Interferometer (NPOI) near Flagstaff, Arizona, makes use of separate smaller optical elements spaced along a Y-array and used simultaneously to simulate an equivalent single large telescope. The instrument is useful in generating and upgrading existing astronomical catalogues and investigating synthetic aperture optical imaging techniques. The NPOI is a joint collaboration between the US Naval Observatory and Naval Research Laboratory in collaboration with the Lowell Observatory. Stellar radiation (visible light) reflects off 35 cm diameter flat mirrors, also known as siderostats, toward a tilt-tip mirror, which reflects a 12 cm diameter beam through a multi-reflection relay transport system. To maximize the reflective area of the siderostat optics and achieve an increase by a factor of 8.5 in light collecting area, a beam compressor is to be installed between the siderostat and fast tip/tilt mirror. However, the present configuration of a prototype beam compressor mount (BCM) vibrates at unacceptable amplitudes, which makes it nearly impossible to optically align the mirrors. This paper presents the results of finite element analyses conducted to quantify the design limitations of the prototype beam compressor mount. The analyses indicated that the current configuration is too soft, with very low fundamental frequencies, which verified the difficulties encountered during alignment tests. Based on these results, design modifications have been proposed to increase the overall structural stiffness of the mount and increase its fundamental frequency of vibration. These modifications will mechanically stabilize the structure for the alignment of the optics, and allow integration of the compressor into the interferometer. The interferometer will then have the capability to capture more light from each siderostat and allow observations of fainter stellar targets. More generally, the results can be useful as a guide for engineers and scientists involved in the design of similar optomechanical structures.

Proceedings Article | 22 July 2010 Paper

Wavefront calibration and correction of an optical train path: a compliant static deformable mirror approach

James Clark, F. Ernesto Penado, Frank Cornelius

Proceedings Volume 7734, 773429 (2010) https://doi.org/10.1117/12.856970

KEYWORDS: Mirrors, Wavefronts, Relays, Adaptive optics, Photovoltaics, Interferometers, Calibration, Wavefront distortions, Deformable mirrors, Actuators

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Proceedings Article | 10 September 2009 Paper

Optimizing the frequency response of a steering mirror mount for interferometry applications

F. Ernesto Penado, James Clark

Proceedings Volume 7424, 742403 (2009) https://doi.org/10.1117/12.825338

KEYWORDS: Mirrors, Composites, Mirror mounts, Foam, Glasses, Aluminum, Solids, Interferometers, Finite element methods, Interferometry

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Proceedings Article | 10 September 2009 Paper

Mirror deformation versus contact area in mounted flat mirrors

James Clark, F. Ernesto Penado, Frank Cornelius

Proceedings Volume 7424, 74240C (2009) https://doi.org/10.1117/12.826747

KEYWORDS: Mirrors, Interferometers, Finite element methods, Phase shifts, Reflectivity, Tolerancing, Prototyping, Coating, Calibration, Observatories

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Proceedings Article | 28 July 2008 Paper

Mount-induced deflections in 8-inch flat mirrors at the Navy Prototype Optical Interferometer

James Clark, F. Ernesto Penado, Michael DiVitorrio, Joshua Walton

Proceedings Volume 7013, 70133K (2008) https://doi.org/10.1117/12.790257

KEYWORDS: Mirrors, Finite element methods, Interferometers, Prototyping, Phase shifts, Tolerancing, Zerodur, Optics manufacturing, Coating, Off axis mirrors

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