Dr. Ronald Holzlöhner Profile

Dr. Ronald Holzlöhner

Laser Physicist at European Southern Observatory

SPIE Involvement:

Author

Publications (33)

Proceedings Article | 29 August 2024 Poster + Paper

A hovercraft to clean large telescope mirrors

Ronald Holzlöhner, Juan Antonio Marrero Hernández

Proceedings Volume 13100, 131005Y (2024) https://doi.org/10.1117/12.3019816

KEYWORDS: Mirrors, Mirror surfaces, Particles, Telescopes, Silver, Contamination, Aluminum mirrors, Aluminum, Large telescopes

Read Abstract +

Proceedings Article | 27 August 2024 Poster + Paper

Seven years of sodium history at Paranal: temporal evolution, statistics, and modelling

P. Haguenauer, R. Holzlöhner

Proceedings Volume 13097, 1309768 (2024) https://doi.org/10.1117/12.3017643

KEYWORDS: Sodium, Adaptive optics, Data modeling, Wavefront sensors, Laser guide stars, Atmospheric modeling

Read Abstract +

The use of artificial laser guide stars (LGS) eliminates the need for a bright natural guide star (NGS) in adaptive optics (AO) systems. High-power lasers are essential components of most modern AO systems. LGS creation depends on exciting sodium (Na) atoms in the upper atmosphere, making the sodium vertical column density (C_Na) a critical parameter. Understanding the return flux from LGSs is vital for designing AO systems, ensuring optimal and stable performance by accurately specifying both the LGS and the AO system. Various studies have focused on sodium availability in the upper atmosphere, showing a strong dependence on the observatory site. It’s well-known that C_Na varies over different timescales, including hours, nights, months, seasons, and years. Given that some of the world’s largest telescopes are located in the Atacama Desert in northern Chile, our goal is to provide C_Na statistics relevant to this region. We use telemetry data from the AO systems at Paranal Observatory (24.6°S, 70.4°W): GALACSI (Ground Atmospheric Layer Adaptive Corrector for Spectroscopic Imaging) and GRAAL (Ground Layer Adaptive Optics system Assisted by Lasers). These data are combined with measurements from two space instruments, SCIA-MACHY (SCanning Imaging Absorption Spectrometer for Atmospheric CHartographY) and OSIRIS (Optical Spectrograph and Infrared Imaging System). We carefully analyse and compare these datasets to develop a statistical model for the temporal variations of C_Na. We confirm that the AO telemetry data from Paranal systems can be used to determine CNa. Continuous measurements from mid-2017 enabled us to identify monthly and yearly variations and availability of Na in the mesopause region. Throughout the full years of measurement, the annual and semi-annual variations consistently align with previously documented findings in atmospheric studies. By meticulously comparing and fitting various long-term datasets, we created a model illustrating C_Na’s evolution over time. Our data processing and model are validated, and the results for Paranal’s latitude show notable agreement with findings from other studies.

Proceedings Article | 26 August 2024 Presentation

Optimization of Protected Silver Coating Recipes for E-ELT Telescope Mirrors (Conference Presentation)

Ronald Holzlöhner, Michele Cirasuolo, Ricardo Parra, Svetlana Shestaeva, Stefan Schwinde

Proceedings Volume 13100, 1310020 (2024) https://doi.org/10.1117/12.3019915

Read Abstract +

Proceedings Article | 30 August 2022 Poster + Presentation + Paper

Detection of discontinuous phase steps with a pyramid wavefront sensor

Deborah Malone, Petr Janout, Samuel Lévêque, Ronald Holzlöhner, Byron Engler, Markus Kasper

Proceedings Volume 12185, 121855B (2022) https://doi.org/10.1117/12.2632347

KEYWORDS: Sensors, Spatial light modulators, Segmented mirrors, Calibration, Signal detection, Wavefront sensors, Phase measurement, Mirrors, Image segmentation

Read Abstract +

Proceedings Article | 29 August 2022 Presentation + Paper

Development of advanced silver coatings for telescope mirrors

S. Schwinde, S. Shestaeva, R. Holzlöhner, G. Willers, R. Schlegel, A. Förster, R. Parra, S. Guisard, O. Sqalli, S. Schröder

Proceedings Volume 12188, 121881X (2022) https://doi.org/10.1117/12.2627710

KEYWORDS: Reflectivity, Silver, Mirrors, Telescopes, Optical coatings, Aluminum, Reflector telescopes, Gemini Observatory, Gold, Ruthenium, Near ultraviolet

Read Abstract +

Proceedings Article | 29 August 2022 Presentation + Paper

Electron microscopy studies of contaminated telescope mirror samples exposed at Paranal

Guido Willers, Ronald Holzlöhner, Volker Naumann, Stefan Schwinde, Stéphane Guisard

Proceedings Volume 12188, 121881Z (2022) https://doi.org/10.1117/12.2627690

KEYWORDS: Particles, Mirrors, Aluminum, Telescopes, Silver, Corrosion, Reflectivity, Chlorine, Glasses, Cements

Read Abstract +

Proceedings Article | 29 August 2022 Presentation + Paper

Active optics upgrade using curvature WFS of VISTA for 4MOST

Ronald Holzlöhner, Jérôme Amiaux, Dionisio Garcia-Herreros, Johann Kolb, Jean-François Pirard, Stefan Sandrock, William Sutherland , Thomas Szeifert, Gérard Zins

Proceedings Volume 12188, 1218818 (2022) https://doi.org/10.1117/12.2627677

KEYWORDS: Telescopes, Stars, Sensors, Zemax, Wavefront sensors, Cameras, Wavefronts, Active optics, Ray tracing, Signal to noise ratio, Wavefront reconstruction

Read Abstract +

Proceedings Article | 25 August 2022 Presentation + Paper

Transient wavefront error from cooled air downwind of telescope spiders

Diogo Martins, Ronald Holzlöhner, Christophe Verinaud, Christophe Kleinclaus

Proceedings Volume 12187, 1218712 (2022) https://doi.org/10.1117/12.2627683

KEYWORDS: Telescopes, Device simulation, Adaptive optics, Computer simulations, Turbulence, Wavefronts, Particles, Mirrors, Large telescopes, Sensors, Radiative energy transfer, Computational fluid dynamics

Read Abstract +

SPIE Journal Paper | 5 April 2022

Structural, thermal, and optical performance analysis applied to subsystems of the European Extremely Large Telescope

Ronald Holzlöhner, Aglaé Kellerer, Ulrich Lampater, Steffan Lewis, Carlo Zanoni

JATIS, Vol. 8, Issue 02, 021504, (April 2022) https://doi.org/10.1117/12.10.1117/1.JATIS.8.2.021504

KEYWORDS: Thermography, Optical components, Sensors, Mirrors, Computer aided design, Motion models, Telescopes, Systems modeling, Integrated modeling, Performance modeling

Read Abstract +

Proceedings Article | 13 December 2020 Presentation

Mitigating wavefront error caused by sky subcooling of the ELT structure

Ronald Holzlöhner, Martin Brinkmann

Proceedings Volume 11445, 114450Y (2020) https://doi.org/10.1117/12.2563285

KEYWORDS: Wavefronts, Telescopes, Surface finishing, 3D modeling, Turbulence, Solids, Mirrors, Computational fluid dynamics, Computer simulations, Device simulation

Read Abstract +

Proceedings Article | 13 December 2020 Presentation

Maximum likelihood co-phasing of segmented mirrors with a pyramid in the visible: simulation vs. experiment

Ronald Holzlöhner, Pierre Janin-Potiron, Benoit Neichel, Aglaé Kellerer, Samuel Lévêque, Vincent Chambouleyron, Thierry Fusco, Victoria Wallauer

Proceedings Volume 11448, 114480S (2020) https://doi.org/10.1117/12.2563287

KEYWORDS: Segmented mirrors, Device simulation, Telescopes, Mirrors, Atmospheric modeling, Optical simulations, Optical benches, Modulation, Wavefront sensors, Optical sensors

Read Abstract +

Proceedings Article | 24 July 2018 Paper

Combined Opto-mechanical analysis for modern optical instruments

J. Heijmans, M. Müller, R. Holzlöhner

Proceedings Volume 10705, 107052D (2018) https://doi.org/10.1117/12.2314778

KEYWORDS: Optical design, Finite element methods, Computer aided design, Ray tracing, Tolerancing, Analytical research, Geometrical optics, Zemax, Optical analysis, Telescopes

Read Abstract +

Proceedings Article | 18 July 2018 Paper

Line of sight mesospheric sodium profiles obtained from the LGS signal for optimal ELT LGS-AO

Joschua Hellemeier, Domenico Bonaccini Calia, Paul Hickson, Thomas Pfrommer, Ron Holzlöhner

Proceedings Volume 10703, 1070340 (2018) https://doi.org/10.1117/12.2312292

KEYWORDS: Sodium, Adaptive optics, Modulation, LIDAR, Continuous wave operation, Telescopes, Wavefront sensors, Laser guide stars, Amplitude modulation, Large telescopes

Read Abstract +

Proceedings Article | 17 July 2018 Paper

Simulations of continuous-wave sodium laser guide stars with polarization modulation at Larmor frequency

Felipe Pedreros Bustos, Ronald Holzlöhner, Simon Rochester, Domenico Bonaccini Calia, Joschua Hellemeier, Dmitry Budker

Proceedings Volume 10703, 107033R (2018) https://doi.org/10.1117/12.2313694

KEYWORDS: Modulation, Polarization, Sodium, Continuous wave operation, Laser guide stars, Mesosphere, Optical pumping

Read Abstract +

Proceedings Article | 13 July 2018 Presentation + Paper

Stray light and thermal self-emission minimization at the ELT

Ronald Holzlöhner, Johan Kosmalski, Stéphane Guisard

Proceedings Volume 10700, 107000I (2018) https://doi.org/10.1117/12.2313314

KEYWORDS: Mirrors, Reflectivity, Coating, Particles, Telescopes, Scattering, Light scattering, Absorption, Silver, Stray light

Read Abstract +

Proceedings Article | 10 July 2018 Presentation + Paper

Meter-class mirror figure metrology using a 24-channel fiber interferometer

Ronald Holzlöhner, Samuel Lévêque, Nicola Di Lieto, Juan-Antonio Marrero Hernández, Andrew Rakich

Proceedings Volume 10706, 107061F (2018) https://doi.org/10.1117/12.2312642

KEYWORDS: Mirrors, Collimators, Metrology, Interferometers, Prototyping, Interferometry, Distance measurement, Telescopes, Finite element methods, Monochromatic aberrations

Read Abstract +

Proceedings Article | 10 July 2018 Paper

Studies towards a directional polychromatic sodium laser guide star

Felipe Pedreros Bustos, Alexander Akulshin, Ronald Holzlöhner, Simon Rochester, Dmitry Budker

Proceedings Volume 10703, 107030R (2018) https://doi.org/10.1117/12.2313757

KEYWORDS: Alkali vapor lasers, Sodium, Mesosphere, Laser guide stars, Infrared radiation, Adaptive optics

Read Abstract +

Proceedings Article | 9 July 2018 Paper

Extremely Large Telescope Prefocal Station A system concept

S. A. Lewis, E. Brunetto, A. Förster, C. Frank, I. Guidolin, S. Guisard, P. Hammersley, R. Holzlöhner, P. Jolley, J. Kosmalski, U. Lampater, E. Marchetti, P. La Penna, T. Pfrommer, P. Zuluaga

Proceedings Volume 10700, 107001B (2018) https://doi.org/10.1117/12.2313535

KEYWORDS: Telescopes, Sensors, Mirrors, Metrology, Wavefront sensors, Error analysis, Cameras, Interfaces, Imaging systems, Wavefronts

Read Abstract +

Proceedings Article | 8 August 2016 Paper

Focal-plane wavefront sensing for active optics in the VST based on an analytical optical aberration model

R. Holzlöhner, S. Taubenberger, A. Rakich, L. Noethe, P. Schipani, K. Kuijken

Proceedings Volume 9906, 99066E (2016) https://doi.org/10.1117/12.2234398

KEYWORDS: Telescopes, Active optics, Wavefront sensors, Point spread functions, Optical aberrations, Stars, Electroluminescent displays, Image quality, Mirrors, Sensors

Read Abstract +

Proceedings Article | 27 July 2016 Paper

Comparison between observation and simulation of sodium LGS return flux with a 20W CW laser on Tenerife

R. Holzlöhner, D. Bonaccini Calia, D. Bello, D. Budker, M. Centrone, I. Guidolin, W. Hackenberg, S. Lewis, G. Lombardi, I. Montilla, F. Pedichini, F. Pedreros Bustos, T. Pfrommer, M. Reyes Garcia Talavera, S. Rochester

Proceedings Volume 9909, 99095E (2016) https://doi.org/10.1117/12.2233072

KEYWORDS: Sodium, Optical simulations, Laser guide stars, Continuous wave operation, Polarization, Laser systems engineering, Laser guide stars, Optical simulations, Magnetism, Laser processing, Fiber lasers, Laser applications

Read Abstract +

Proceedings Article | 27 July 2016 Paper

Sodium vapor cell laser guide star experiments for continuous wave model validation

Felipe Pedreros Bustos, Ronald Holzlöhner, Dmitry Budker, Steffan Lewis, Simon Rochester

Proceedings Volume 9909, 99095P (2016) https://doi.org/10.1117/12.2232524

KEYWORDS: Absorption, Sodium, Laser guide stars, Continuous wave operation, Polarization, Electroluminescent displays, Chemical species, Magnetism, Mesosphere, Spectrum analysis

Read Abstract +

Proceedings Article | 7 August 2014 Paper

Fast active optics control of wide-field telescopes based on science image analysis

R. Holzlöhner, A. Rakich, L. Noethe, K. Kuijken, P. Schipani

Proceedings Volume 9151, 91512I (2014) https://doi.org/10.1117/12.2056121

KEYWORDS: Telescopes, Electroluminescent displays, Stars, Monochromatic aberrations, Point spread functions, Wavefronts, Active optics, Mirrors, Zemax, Galactic astronomy

Read Abstract +

Proceedings Article | 7 August 2014 Paper

Assembly and test results of the AOF laser guide star units at ESO

W. Hackenberg, D. Bonaccini Calia, B. Buzzoni, M. Comin, C. Dupuy, F. Gago, I. Guidolin, R. Guzman, R. Holzloehner, L. Kern, J. Kirchbauer, S. Lewis, J. Lizon, S. McLay, T. Pfrommer, M. Quattri, J. Quentin, R. Ridings

Proceedings Volume 9148, 91483O (2014) https://doi.org/10.1117/12.2057167

KEYWORDS: Telescopes, Mirrors, Laser guide stars, Interfaces, Calibration, Adaptive optics, Wavefronts, Temperature metrology, Camera shutters, Lasers

Read Abstract +

Proceedings Article | 4 August 2014 Paper

Impact of sodium layer variations on the performance of the E-ELT MCAO module

L. Schreiber, E. Diolaiti, C. Arcidiacono, T. Pfrommer, R. Holzlöhner, M. Lombini, P. Hickson

Proceedings Volume 9148, 91486Q (2014) https://doi.org/10.1117/12.2056483

KEYWORDS: Sodium, Adaptive optics, Telescopes, Laser guide stars, Wavefronts, Device simulation, Temporal resolution, Monochromatic aberrations, Stars, Performance modeling

Read Abstract +

Proceedings Article | 13 September 2012 Paper

Investigations of long pulse sodium laser guide stars

Rachel Rampy, Donald Gavel, Simon Rochester, Ronald Holzlöhner

Proceedings Volume 8447, 84474L (2012) https://doi.org/10.1117/12.926621

KEYWORDS: Sodium, Chemical species, Telescopes, Adaptive optics, Mesosphere, Fiber lasers, Laser guide stars, Dye lasers, Optical simulations, Device simulation

Read Abstract +

Proceedings Article | 13 September 2012 Paper

Simulations of pulsed sodium laser guide stars: an overview

Ronald Holzlöhner, Simon Rochester, Domenico Bonaccini Calia, Dmitry Budker, Thomas Pfrommer, James Higbie

Proceedings Volume 8447, 84470H (2012) https://doi.org/10.1117/12.924882

KEYWORDS: Sodium, Pulsed laser operation, Gemini Observatory, Optical simulations, Laser guide stars, Polarization, Continuous wave operation, Chemical species, Phase modulation, Physics

Read Abstract +

Proceedings Article | 13 September 2012 Paper

The ESO transportable LGS Unit for measurements of the LGS photon return and other experiments

D. Bonaccini Calia, I. Guidolin, A. Friedenauer, M. Hager, V. Karpov, T. Pfrommer, R. Holzlöhner, S. Lewis, W. Hackenberg, G. Lombardi, M. Centrone, F. Pedichini

Proceedings Volume 8450, 84501R (2012) https://doi.org/10.1117/12.926898

KEYWORDS: Telescopes, Sodium, Continuous wave operation, Pulsed laser operation, Polarization, Laser guide stars, Adaptive optics, Wavefront sensors, Wavefronts, Receivers

Read Abstract +

Proceedings Article | 28 July 2010 Paper

Laser guide star return flux simulations based on observed sodium density profiles

Ronald Holzlöhner, Simon Rochester, Thomas Pfrommer, Domenico Bonaccini Calia, Dmitry Budker, James Higbie, Wolfgang Hackenberg

Proceedings Volume 7736, 77360V (2010) https://doi.org/10.1117/12.856721

KEYWORDS: Sodium, Optical simulations, Mesosphere, Telescopes, Laser guide stars, Tantalum, Magnetism, Chemical species, Adaptive optics, Device simulation

Read Abstract +

Proceedings Article | 10 July 2008 Paper

Effect of the geomagnetic field on the intensity of sodium laser guide stars

N. Moussaoui, R. Holzlöhner, W. Hackenberg, D. Bonaccini Calia

Proceedings Volume 7015, 70152W (2008) https://doi.org/10.1117/12.803921

KEYWORDS: Sodium, Magnetism, Chemical species, Optical pumping, Laser guide stars, Absorption, Laser beam propagation, Polarization, Telescopes, Electrons

Read Abstract +

Proceedings Article | 10 July 2008 Paper

Physical optics modeling and optimization of laser guide star propagation

Ronald Holzlöhner, Domenico Bonaccini Calia, Wolfgang Hackenberg

Proceedings Volume 7015, 701521 (2008) https://doi.org/10.1117/12.790907

KEYWORDS: Sodium, Atmospheric propagation, Telescopes, Adaptive optics, Device simulation, Point spread functions, Wavefront sensors, Turbulence, Light wave propagation, Wave propagation

Read Abstract +

Proceedings Article | 18 September 2007 Paper

The European LGS test facility

R. Myers, D. Bonaccini Calia, N. Devaney, S. Esposito, S. Goodsell, A. Goncharov, J. Guerra, H. Guillet de Chatellus, M. Harrison, R. Holzloehner, E. Marchetti, T. Morris, E. Pinna, J.-P. Pique, S. Rabien, M. Reyes, E. Ribak, R. Rutten, H. Schnetler, M. Strachan, R. Stuik, R. G. Talbot, S. Tulloch

Proceedings Volume 6691, 66910Q (2007) https://doi.org/10.1117/12.735804

KEYWORDS: Adaptive optics, Telescopes, Sodium, Control systems, Space telescopes, Wavefront sensors, Lanthanum, Laser guide stars, Wavefronts, Laser applications

Read Abstract +

Proceedings Article | 5 February 2007 Paper

FEM investigation of leaky modes in hollow core photonic crystal fibers

Jan Pomplun, Ronald Holzlöhner, Sven Burger, Lin Zschiedrich, Frank Schmidt

Proceedings Volume 6480, 64800M (2007) https://doi.org/10.1117/12.700495

KEYWORDS: Finite element methods, Photonic crystal fibers, Cladding, Optical fibers, Refractive index, Adaptive optics, Photonic crystals, Chemical elements, Interfaces, Numerical analysis

Read Abstract +

Proceedings Article | 27 June 2006 Paper

Ultra-low loss hollow-core photonic crystal fibers at 589 nm for LGS-assisted AO

Ronald Holzlöhner, Brian Mangan, Domenico Bonaccini Calia, Wolfgang Hackenberg

Proceedings Volume 6272, 62724B (2006) https://doi.org/10.1117/12.673179

KEYWORDS: Signal attenuation, Cladding, Photonic crystal fibers, Structured optical fibers, Finite element methods, Glasses, Adaptive optics, Capillaries, Sodium, Laser guide stars

Read Abstract +

Showing 5 of 33 publications

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

Keywords/Phrases

Search In:

Publication Years