Dr. Joe Ritter Profile

Dr. Joe Ritter

Physicist/Optical Engineer/Lab Director at Neoteric Advanced Technologies

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Author

Publications (13)

Proceedings Article | 29 August 2022 Presentation + Paper

An emerging hybrid technology toward ultra-light and self-correcting, “live” mirrors

Gil Moretto, K. Thetpraphi, J-F. Capsal, J.R. Kuhn, D. Audgier, M. Langlois, C. Graf, J. Ritter, R. Rebolo, N. Lodieu, Y. Zhou, K. Lewis

Proceedings Volume 12188, 121880D (2022) https://doi.org/10.1117/12.2629589

KEYWORDS: Mirrors, Optics manufacturing, Actuators, Telescopes, Electroactive polymers, Telecommunications, Space telescopes, Prototyping, Solar energy systems, Additive manufacturing

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Proceedings Article | 29 August 2022 Poster + Paper

Small-ELF Telescope: opto-mechanical design and application of tensegrity

Ye Zhou, T. Lee, J. Kuhn, I. Cunnyngham, S. Jefferies, M. Langlois, K. Lewis, N. Lodieu, G. Moretto, R. Rebolo, J. Ritter, R. Swindle, S. Salata, M. Rios, R. Diego

Proceedings Volume 12182, 121822J (2022) https://doi.org/10.1117/12.2630606

KEYWORDS: Telescopes, Mirrors, Optical instrument design, Error analysis, Actuators, Adaptive optics, Wavefronts, Structural design, Assembly tolerances, Optomechanical design

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Proceedings Article | 26 August 2022 Presentation + Paper

The small-ELF project: toward an ultra-large coronagraphic optical receiver

Jeff Kuhn, Jean-Fabien Capsal, Ian Cunnyngham, Maud Langlois, Kevin Lewis, Nicolas Lodieu, Gil Moretto, Rafael Rebolo, Joe Ritter, Ryan Swindle, Ye Zhou, Stuart Jefferies, Kritsadi Thetprapi, David Audigier, Justin Fletcher

Proceedings Volume 12182, 121820G (2022) https://doi.org/10.1117/12.2629645

KEYWORDS: Wavefronts, Mirrors, Glasses, Telescopes, Surface finishing, Polishing, Image segmentation, Stars, Coronagraphy, Chemical elements

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Proceedings Article | 6 March 2014 Paper

Recent developments in the production of spin-cast epoxy mirrors

K. Lisa Brodhacker, Joe Ritter, Andrew La Croix, Bruce Holenstein, Russell Genet

Proceedings Volume 8971, 89710O (2014) https://doi.org/10.1117/12.2044612

KEYWORDS: Mirrors, Epoxies, Telescopes, System on a chip, Aluminum, Space telescopes, Foam, Polymers, Coating, Glasses

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Proceedings Article | 27 August 2009 Paper

Working model of a gossamer membrane spectrographic space telescope

Thomas Ditto, Joe Ritter, John Valliant

Proceedings Volume 7436, 74360H (2009) https://doi.org/10.1117/12.826377

KEYWORDS: Space telescopes, Telescopes, Spectroscopy, Mirrors, Light emitting diodes, Astronomical telescopes, Lenses, Stars, Space mirrors, Diffraction

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Proceedings Article | 26 August 2009 Paper

Photonic muscle active optics for space telescopes (active optics with 10[sup]23[/sup] actuators)

Joe Ritter

Proceedings Volume 7436, 74360N (2009) https://doi.org/10.1117/12.826504

KEYWORDS: Mirrors, Polymers, Space telescopes, Active optics, Raman spectroscopy, Actuators, Molecules, Wavefronts, Control systems, Absorption

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Presented is a novel optical system using Cis-Trans photoisomerization where nearly every molecule of a mirror substrate is itself an optically powered actuator. Primary mirrors require sub-wavelength figure (shape) error in order to achieve acceptable Strehl ratios. Traditional telescopy methods require rigid and therefore heavy mirrors and reaction structures as well as proportionally heavy and expensive spacecraft busses and launch vehicles. Areal density can be reduced by increasing actuation density. Making every molecule of a substrate an actuator approaches the limit of the areal density vs actuation design trade space. Cis-Trans photoisomerization, a reversible reorganization of molecular structure induced by light, causes a change in the shape and volume of azobenzene based molecules. Induced strain in these "photonic muscles" can be over 40%. Forces are pico-newtons/molecule. Although this molecular limit is not typically multiplied in aggregate materials we have made, considering the large number of molecules in a mole, future optimized systems may approach this limit In some π-π* mixed valence azo-polymer membranes we have made photoisomerization causes a highly controllable change in macroscopic dimension with application of light. Using different wavelengths and polarizations provides the capability to actively reversibly and remotely control membrane mirror shape and dynamics using low power lasers, instead of bulky actuators and wires, thus allowing the substitution of optically induced control for rigidity and mass. Areal densities of our photonic muscle mirrors are approximately 100 g/m2. This includes the substrate and actuators (which are of course the same). These materials are thin and flexible (similar to saran wrap) so high packing ratios are possible, suggesting the possibility of deployable JWST size mirrors weighing 6 kilograms, and the possibility of ultralightweight space telescopes the size of a football field. Photons weigh nothing. Why must even small space telescopes weigh tons? Perhaps they do not.

Proceedings Article | 23 July 2008 Paper

Million object spectrograph

Thomas Ditto, Joseph Ritter

Proceedings Volume 7018, 70182R (2008) https://doi.org/10.1117/12.790244

KEYWORDS: Spectrographs, Telescopes, Mirrors, Diffraction gratings, Spectral resolution, Molybdenum, Stars, Spectroscopy, Diffraction, Space telescopes

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Proceedings Article | 12 July 2008 Paper

Phase errors in gossamer membrane primary objective gratings

Thomas Ditto, Joseph Ritter

Proceedings Volume 7010, 70104F (2008) https://doi.org/10.1117/12.790222

KEYWORDS: Tolerancing, Space telescopes, Mirrors, Diffraction gratings, Telescopes, Diffraction, Spectral resolution, Spatial resolution, Reflection, Glasses

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Proceedings Article | 12 July 2008 Paper

Large ultra-lightweight photonic muscle membrane mirror telescope

Joseph Ritter, Andrea Baer, Thomas Ditto

Proceedings Volume 7010, 70102K (2008) https://doi.org/10.1117/12.790212

KEYWORDS: Mirrors, Polymers, Space telescopes, Raman spectroscopy, Wavefronts, Infrared radiation, Absorption, Active optics, Molecules, Control systems

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Proceedings Article | 10 July 2008 Paper

Ultra low wind resistance enclosure for a 100-m telescope

Thomas Ditto, Joseph Ritter

Proceedings Volume 7012, 70123I (2008) https://doi.org/10.1117/12.790268

KEYWORDS: Telescopes, Mirrors, Diffraction gratings, Spatial resolution, Spectrographs, Space telescopes, Zemax, Holography, Diffraction, Resistance

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Proceedings Article | 9 July 2008 Paper

10 meter airborne observatory

Thomas Ditto, Joseph Ritter

Proceedings Volume 7014, 70142J (2008) https://doi.org/10.1117/12.790261

KEYWORDS: Observatories, Telescopes, Mirrors, Spectrographs, Aerodynamics, Turbulence, Zemax, Spectral resolution, Diffraction gratings, Spectroscopy

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Proceedings Article | 30 August 2005 Paper

Photonic muscles: optically controlled active optics

Joe Ritter, Jim Brozik, Solomon Basame, Mike Fallbach, Larry Bradford, Dennis Douglas, Gilda Miner

Proceedings Volume 5894, 589419 (2005) https://doi.org/10.1117/12.618269

KEYWORDS: Polymers, Active optics, Mirrors, Wavefronts, Ocean optics, Optics manufacturing, Metals, Metamaterials, Control systems, Adaptive optics

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Proceedings Article | 30 January 2004 Paper

Novel photomechanical actuators

Joseph Ritter, James Brozik, Luke Emmert, Mike Fallbach, Rodney Bradford, Donald Leo, Ken Meissner

Proceedings Volume 5166, (2004) https://doi.org/10.1117/12.512022

KEYWORDS: Active optics, Mirrors, Polymers, Control systems, Wavefronts, Space telescopes, Imaging spectroscopy, Actuators, Optical components, Radio optics

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Showing 5 of 13 publications

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