Dr. Urs U. Graf Profile

Dr. Urs U. Graf

Research Scientist at Univ zu Köln

SPIE Involvement:

Author

Publications (26)

Proceedings Article | 26 August 2022 Presentation + Paper

Presentation + Paper

CCAT-prime/FYST: a status report on the ultra-widefield submillimeter observatory on Cerro Chajnantor

G. Stacey, Nicholas Battaglia, Scott Chapman, Steve Choi, Laura Fissel, Urs Graf, Terry Herter, Douglas Johnstone, P. Daniel Meerburg, Michael Niemack, Thomas Nikola, Stephen Parshley, Dominik Riechers, Robert Simon, Eve Vavagiakis

Proceedings Volume 12182, 1218210 (2022) https://doi.org/10.1117/12.2630380

KEYWORDS: Galactic astronomy, Telescopes, Polarization, Clouds, Mirrors, Spectroscopy, Sensors, Cameras, Polarimetry, Galaxy evolution, Galaxy groups and clusters, Physical cosmology

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Proceedings Article | 14 December 2020 Poster + Paper

Poster + Paper

Towards ultra-broadband heterodyne interferometry in the N- and Q-bands

Ernest Michael, Ramin Emadi, Enrique Moreno, Lucas Labadie, Cornelia Honingh, Karl Jacobs, Urs Graf, Stephan Schlemmer, Jürgen Stutzki

Proceedings Volume 11446, 114462O (2020) https://doi.org/10.1117/12.2563069

KEYWORDS: Heterodyning, Interferometry, Telescopes, Graphene, Optical correlators, Dense wavelength division multiplexing, Laser development, Mid-IR, Optical spheres, Planets

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Proceedings Article | 13 December 2020 Poster + Paper

Poster + Paper

Holographic surface measurement system for the Fred Young Submillimeter Telescope

Xiaodong Ren, Pablo Astudillo, Urs Graf, Richard Hills, Sebastian Jorquera, Bojan Nikolic, Stephen Parshley, Nicolás Reyes, Lars Weikert

Proceedings Volume 11445, 114456D (2020) https://doi.org/10.1117/12.2560459

KEYWORDS: Telescopes, Holography, Receivers, Wavefronts, Data modeling, Off axis mirrors, Spectroscopy, Reflectors

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Proceedings Article | 9 July 2018 Presentation + Paper

Presentation + Paper

CCAT-Prime: science with an ultra-widefield submillimeter observatory on Cerro Chajnantor

G. Stacey, M. Aravena, K. Basu, N. Battaglia, B. Beringue, F. Bertoldi, J. R. Bond, P. Breysse, R. Bustos, S. Chapman, D. Chung, N. Cothard, J. Erler, M. Fich, S. Foreman, P. Gallardo, R. Giovanelli, U. Graf, M. Haynes, R. Herrera-Camus, T. Herter, R. Hložek, D. Johnstone, L. Keating, B. Magnelli, D. Meerburg, J. Meyers, N. Murray, M. Niemack, T. Nikola, M. Nolta, S. Parshley, D. Riechers, P. Schilke, D. Scott, G. Stein, J. Stevens, J. Stutzki, E. Vavagiakis, M. Viero

Proceedings Volume 10700, 107001M (2018) https://doi.org/10.1117/12.2314031

KEYWORDS: Galactic astronomy, Stars, Telescopes, Spectroscopy, Carbon monoxide, Cameras, Polarization, Astronomy, Bolometers

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Proceedings Article | 6 July 2018 Paper

Paper

CCAT-prime: a novel telescope for sub-millimeter astronomy

Stephen Parshley, Jörg Kronshage, James Blair, Terry Herter, Mike Nolta, Gordon Stacey, Andrew Bazarko, Frank Bertoldi, Ricardo Bustos, Donald Campbell, Scott Chapman, Nicolas Cothard, Mark Devlin, Jens Erler, Michel Fich, Patricio Gallardo, Riccardo Giovanelli, Urs Graf, Scott Gramke, Martha Haynes, Richard Hills, Michele Limon, Jeffrey Mangum, Jeff McMahon, Michael Niemack, Thomas Nikola, Markus Omlor, Dominik Riechers, Karl Steeger, Jürgen Stutzki, Eve Vavagiakis

Proceedings Volume 10700, 107005X (2018) https://doi.org/10.1117/12.2314046

KEYWORDS: Telescopes, Mirrors, Optical instrument design, Device simulation, Observatories, Astronomical telescopes, Radio telescopes, Reflector telescopes, Mirror structures, Structural design

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Proceedings Article | 19 August 2014 Paper

Paper

Optics and cryogenics for the 1.1 THz multi-pixel heterodyne receiver for APEX

Norma Hurtado, Urs Graf, Henning Adams, C. Honingh, Karl Jacobs, Patrick Pütz, Rolf Güsten, Jürgen Stutzki

Proceedings Volume 9153, 915327 (2014) https://doi.org/10.1117/12.2055563

KEYWORDS: Receivers, Mirrors, Telescopes, Terahertz radiation, Aluminum, Computer aided design, Heterodyning, Cryogenics, Thermography, Polarizers

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The 1.1 THz multi-pixel heterodyne receiver will be mounted in the Nasmyth A cabin of the 12 m APEX telescope on the Chajnantor plateau, 5000 meters altitude in northern Chile. The receiver will cover the spectral window of 1000 - 1080 GHz, where important spectral lines like CO 9-8 at 1036.9 GHz, a tracer of warm and dense gas and OH+ at 1033 GHz and NH+ at 1012.6 GHz, both important for the study of chemical networks in the ISM, are located. The multi-pixel receiver greatly enhances the science output under the difficult observing conditions in this frequency range. Two 9-pixel focal plane sub-arrays on orthogonal polarizations are installed in easily removable cartridges. We developed a new thermal link to connect the cartridges to the cryostat. Our thermal link is an all-metal design: aluminum and Invar. All the optics is fully reflective, thus avoiding the absorption and reflection losses of dielectric lenses and reducing standing waves in the receiver. To guaranty internal optics alignment, we employ a monolithic integrated optics approach for the cold optics and the Focal Plane Unit (FPU) optics modeled after the CHARM (Compact Heterodyne Array Receiver Module) concept. The receiver uses synthesizer-driven solid-state local oscillators (LO) and the mixers will be balanced SIS mixers, which are essentially based on the design of the on-chip balanced SIS mixers at 490 GHz developed in our institute. Singleended HEB mixers are used for the laboratory tests of the optics. The LO power distribution is accommodated behind the FPU optics. It is composed of the LO optics, which includes a collimating Fourier grating, and an LO distribution plate to supply LO signal to each of the 9 pixels of the sub-array. Different options for the LO coupling design and fabrication are being analyzed and will be based on in-house hybrid waveguide/planar technology. We summarize the receiver project with emphasis on the cryogenics and the optics and present laboratory test results of the cryogenics, including the thermal link's performance. Beam pattern measurements of the receiver optics are scheduled for the coming days, but unfortunately could not be included in the current paper.

Proceedings Article | 28 July 2010 Paper

Paper

The Stratospheric THz Observatory (STO)

C. Walker, C. Kulesa, P. Bernasconi, H. Eaton, N. Rolander, C. Groppi, J. Kloosterman, T. Cottam, D. Lesser, C. Martin, A. Stark, D. Neufeld, C. Lisse, D. Hollenbach, J. Kawamura, P. Goldsmith, W. Langer, H. Yorke, J. Sterne, A. Skalare, I. Mehdi, S. Weinreb, J. Kooi, J. Stutzki, U. Graf, M. Brasse, C. Honingh, R. Simon, M. Akyilmaz, P. Puetz, Mark Wolfire

Proceedings Volume 7733, 77330N (2010) https://doi.org/10.1117/12.857765

KEYWORDS: Telescopes, Terahertz radiation, Receivers, Observatories, Spectroscopy, Electronics, Signal processing, Stars, Clouds, Control systems

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Proceedings Article | 25 July 2008 Paper

Paper

GREAT: a first light instrument for SOFIA

S. Heyminck, R. Güsten, P. Hartogh, H.-W. Hübers, J. Stutzki, U. Graf

Proceedings Volume 7014, 701410 (2008) https://doi.org/10.1117/12.788273

KEYWORDS: Receivers, Terahertz radiation, Channel projecting optics, Electronics, Astronomy, Spectrometers, Adaptive optics, Optical amplifiers, System integration, Heterodyning

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Proceedings Article | 19 July 2008 Paper

Paper

Submillimeter heterodyne arrays for APEX

R. Güsten, A. Baryshev, A. Bell, A. Belloche, U. Graf, H. Hafok, S. Heyminck, S. Hochgürtel, C. Honingh, K. Jacobs, C. Kasemann, B. Klein, T. Klein, A. Korn, I. Krämer, C. Leinz, A. Lundgren, K. Menten, K. Meyer, D. Muders, F. Pacek, D. Rabanus, F. Schäfer, P. Schilke, G. Schneider, J. Stutzki, G. Wieching, A. Wunsch, F. Wyrowski

Proceedings Volume 7020, 702010 (2008) https://doi.org/10.1117/12.788271

KEYWORDS: Telescopes, Receivers, Heterodyning, Spectrometers, Raster graphics, Calibration, Sensors, Field programmable gate arrays, Atmospheric optics, Optical filters

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Proceedings Article | 26 September 2007 Paper

Paper

GREAT: the German first light heterodyne instrument for SOFIA

Urs Graf, Stefan Heyminck, Rolf Güsten, Paul Hartogh, Heinz-Wilhelm Hübers, Jürgen Stutzki, Jérôme Faist, Milan Fischer, Karl Jacobs, Martin Philipp, David Rabanus, Alexej Semenov, Peter van der Wal, Armin Wagner-Gentner, Christoph Walther, Martina Wiedner

Proceedings Volume 6678, 66780K (2007) https://doi.org/10.1117/12.768027

KEYWORDS: Terahertz radiation, Receivers, Quantum cascade lasers, Oscillators, Heterodyning, Spectrometers, Electronics, Spectral resolution, Photography, Observatories

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Proceedings Article | 27 June 2006 Paper

Paper

GREAT: the German first light heterodyne instrument for SOFIA

Urs Graf, Stefan Heyminck, Rolf Güsten, Paul Hartogh, Heinz-Wilhelm Hübers, Karl Jacobs, Martin Philipp, David Rabanus, Hans-Peter Röser, Jürgen Stutzki, Peter van der Wal, Armin Wagner-Gentner

Proceedings Volume 6275, 62750K (2006) https://doi.org/10.1117/12.673168

KEYWORDS: Terahertz radiation, Receivers, Oscillators, Heterodyning, Spectrometers, Spectral resolution, Astronomy, Photography, Bolometers, Calibration

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Proceedings Article | 8 October 2004 Paper

Paper

First results from DesertSTAR: a 7-pixel 345-GHz heterodyne array receiver for the Heinrich Hertz Telescope

Christopher Groppi, Christopher Walker, Craig Kulesa, Dathon Golish, Abigail Hedden, Gopal Narayanan, Arthur Lichtenberger, Jacob Kooi, Urs Graf, Stefan Heyminck

Proceedings Volume 5498, (2004) https://doi.org/10.1117/12.552492

KEYWORDS: Receivers, Telescopes, Computing systems, Heterodyning, Waveguides, Cryogenics, Control systems, Computer aided design, Mirrors, Optical amplifiers

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Proceedings Article | 8 October 2004 Paper

Paper

GREAT optics

Armin Wagner-Gentner, Urs Graf, Martin Philipp, David Rabanus, Jurgen Stutzki

Proceedings Volume 5498, (2004) https://doi.org/10.1117/12.551236

KEYWORDS: Receivers, Optics manufacturing, Mirrors, Telescopes, Integrated optics, Terahertz radiation, Off axis mirrors, Optical testing, Beam splitters, Optical alignment

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Proceedings Article | 8 October 2004 Paper

Paper

Cryogenic design of KOSMA's SOFIA terahertz array receiver (STAR)

David Rabanus, Urs Graf, Martin Philipp, Jurgen Stutzki, Armin Wagner-Gentner

Proceedings Volume 5498, (2004) https://doi.org/10.1117/12.551311

KEYWORDS: Stars, Receivers, Oscillators, Cryogenics, Terahertz radiation, Telescopes, Heterodyning, Integrated optics, Multiplexing, Space telescopes

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Proceedings Article | 8 October 2004 Paper

Paper

1.4-THz receiver for APEX and for GREAT on SOFIA

Gundolf Schmidt, Frank Bielau, Urs Graf, C. Honingh, Karl Jacobs, Katharina Rettenbacher, Jurgen Stutzki, Martina Wiedner

Proceedings Volume 5498, (2004) https://doi.org/10.1117/12.550334

KEYWORDS: Receivers, Terahertz radiation, Telescopes, Astronomy, Stars, Carbon monoxide, Mirrors, Observatories, Heterodyning, Oscillators

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Proceedings Article | 3 March 2003 Paper

Paper

STAR: SOFIA terahertz array receiver

Urs Graf, Stefan Heyminck, D. Rabanus, Karl Jacobs, Rudolf Schieder, Juergen Stutzki

Proceedings Volume 4857, (2003) https://doi.org/10.1117/12.458821

KEYWORDS: Receivers, Stars, Oscillators, Integrated optics, Polarization, Mirrors, Terahertz radiation, Beam splitters, Bolometers, Heterodyning

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Proceedings Article | 3 March 2003 Paper

Paper

GREAT: the German Receiver for Astronomy at Terahertz Frequencies

Rolf Guesten, Ivan Camara, Paul Hartogh, Heinz-Wilhelm Huebers, Urs Graf, Karl Jacobs, Christoph Kasemann, Hans-Peter Roeser, Rudolf Schieder, Gert Schnieder, Oliver Sievertz, Juergen Stutzki, Geronimo Villanueva, Armin Wagner, Peter van der Wal, Achim Wunsch

Proceedings Volume 4857, (2003) https://doi.org/10.1117/12.458820

KEYWORDS: Spectroscopy, Receivers, Astronomy, Data acquisition, Heterodyning, Oscillators, Spectroscopes, Terahertz radiation, Beam splitters, Spectral resolution

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Proceedings Article | 17 February 2003 Paper

Paper

SMART: the KOSMA submillimeter array receiver for two frequencies

Urs Graf, Stefan Heyminck, Ernest Michael, S. Stanko, C. Honingh, Karl Jacobs, Rudolf Schieder, Juergen Stutzki, B. Vowinkel

Proceedings Volume 4855, (2003) https://doi.org/10.1117/12.459669

KEYWORDS: Receivers, Telescopes, Mirrors, Electronics, Astronomy, Niobium, Beam splitters, Space telescopes, Photography, Control systems

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Proceedings Article | 17 February 2003 Paper

Paper

Desert STAR: a 7-pixel 345-GHz heterodyne array receiver for the Heinrich Hertz Telescope

Christopher Groppi, Christopher Walker, Craig Kulesa, Dathon Golish, Abigail Hedden, P. Gensheimer, Gopal Narayanan, Arthur Lichtenberger, Urs Graf, Stefan Heyminck

Proceedings Volume 4855, (2003) https://doi.org/10.1117/12.459361

KEYWORDS: Receivers, Telescopes, Computer aided design, Heterodyning, Waveguides, Computing systems, Temperature metrology, Stars, Mirrors, Electronics

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Proceedings Article | 17 February 2003 Paper

Paper

Photogrammetric surface measurement of the KOSMA 3-m telescope

M. Miller, Urs Graf, R. Kinzel, C. Kramer, M. Lettau, K. Stenvers, Juergen Stutzki

Proceedings Volume 4855, (2003) https://doi.org/10.1117/12.477271

KEYWORDS: Telescopes, Mirrors, Cameras, Reflectors, Photogrammetry, 3D metrology, 3D acquisition, Jupiter, Aluminum, Actuators

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Proceedings Article | 20 June 2000 Paper

Paper

SOFIA terahertz array receiver (STAR)

Ernest Michael, Urs Graf, C. Honingh, K. Jacobs, F. Lewen, Rudolf Schieder, Juergen Stutzki

Proceedings Volume 4014, (2000) https://doi.org/10.1117/12.389127

KEYWORDS: Receivers, Stars, Mirrors, Oscillators, Terahertz radiation, Carbon, Telescopes, Sensors, Polarization, Bolometers

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Proceedings Article | 20 June 2000 Paper

Paper

Reflection gratings as THz local oscillator multiplexer

Stefan Heyminck, Urs Graf

Proceedings Volume 4014, (2000) https://doi.org/10.1117/12.389092

KEYWORDS: Diffraction gratings, Diffraction, Receivers, Beam splitters, Oscillators, Optical design, Manufacturing, Reflection, Multiplexers, Terahertz radiation

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Proceedings Article | 20 June 2000 Paper

Paper

GREAT: the first-generation German heterodyne receiver for SOFIA

Rolf Guesten, Paul Hartogh, Heinz-Wilhelm Huebers, Urs Graf, K. Jacobs, Hans-Peter Roeser, Frank Schaefer, Rudolf Schieder, Ronald Stark, Juergen Stutzki, Peter Van der Wal, Achim Wunsch

Proceedings Volume 4014, (2000) https://doi.org/10.1117/12.389122

KEYWORDS: Terahertz radiation, Heterodyning, Spectroscopy, Receivers, Astronomy, Spectral resolution, Sensors, Oscillators, Spectroscopes, Acousto-optics

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Proceedings Article | 31 July 1998 Paper

Paper

Array receiver development at KOSMA for the submillimeter and terahertz spectral range

Urs Graf, S. Haas, C. Honingh, K. Jacobs, Rudolf Schieder, Juergen Stutzki

Proceedings Volume 3357, (1998) https://doi.org/10.1117/12.317351

KEYWORDS: Receivers, Terahertz radiation, Oscillators, Telescopes, Mirrors, Waveguides, Beam splitters, Bolometers, Heterodyning, Astronomy

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Proceedings Article | 31 July 1998 Paper

Paper

New KOSMA 3-m telescope

C. Kramer, Cuno Degiacomi, Urs Graf, Richard Hills, M. Miller, Rudolf Schieder, Nicholas Schneider, Juergen Stutzki, Gisbert Winnewisser

Proceedings Volume 3357, (1998) https://doi.org/10.1117/12.317403

KEYWORDS: Telescopes, Receivers, Mirrors, Reflectors, Holography, Spectrometers, Observatories, Aluminum, Algorithm development, Transmitters

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Proceedings Article | 17 August 1994 Paper

Paper

Optimized streak-camera system: wide excitation range and extended time scale for fluorescence lifetime measurement

Urs Graf, Christof Buehler, Michael Betz, Herbert Zuber, M. Anliker

Proceedings Volume 2137, (1994) https://doi.org/10.1117/12.182729

KEYWORDS: Luminescence, Spectral resolution, Streak cameras, Spectrographs, Pulsed laser operation, Diffraction gratings, Time resolved spectroscopy, Imaging systems, Sapphire lasers, Autoregressive models

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Showing 5 of 26 publications

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