Dr. Harro Hagedorn Profile

Dr. Harro Hagedorn

Head of the R&D Dept at Bühler Alzenau GmbH

SPIE Involvement:

Author

Publications (27)

Proceedings Article | 24 June 2024 Presentation + Paper

Advances in direct monochromatic monitoring for the DUV range

Detlef Arhilger, Harro Hagedorn, Alfons Zöller

Proceedings Volume 13020, 130200Q (2024) https://doi.org/10.1117/12.3021834

KEYWORDS: Ultraviolet radiation, Optical sensing, Coating, Deep ultraviolet, UV optics, Lamps, Plasma, Glasses, Film thickness

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Proceedings Article | 24 June 2024 Presentation + Paper

High-precision volume manufacturing of optical interference filters on 300mm wafers

Stephan Mingels, Martin Stapp, Torsten Schmauder, Navas Kutty, Harro Hagedorn

Proceedings Volume 13020, 1302003 (2024) https://doi.org/10.1117/12.3017668

KEYWORDS: Coating, Sputter deposition, Optics manufacturing, Coating thickness

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Proceedings Article | 24 June 2024 Paper

Improved polychromatic optical monitoring strategies of thin-film optical filters

Lucas Arsac, Fabien Lemarchand, Detlef Arhilger, Harro Hagedorn, Janis Zideluns, Julien Lumeau

Proceedings Volume 13020, 130200Y (2024) https://doi.org/10.1117/12.3017181

KEYWORDS: Bandpass filters, Transmittance, Optical filters, Refractive index, Error analysis, Design, Algorithm development, Thin films, Physical vapor deposition

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Optical interference filters allow achieving a wide range of spectral functions. To match with the theoretical performances, fabrication processes require accurate control of each of the layers’ thicknesses and precise refractive index knowledge. However, despite highly stable deposition process, thickness errors tend to accumulate as the number of deposited layers increases, which in turn can lead to severe degradation of the spectral response. Optical monitoring is one the common techniques used to reduce layer thickness errors during deposition. It consists of measuring the filter transmittance, at one or several monitoring wavelengths, and studying its variation during the whole deposition process. Those signals give real-time information on the spectral performances, and in turns, on the deposited optical thickness of the layers. Indeed, for a given filter, the monitoring system can compute the theoretical optical signal during the process and compare it with real-time measurement. Algorithms implemented in this system are then able to at least partially compensate thickness errors from the previous layers, by correcting the expected cut-off points for the current and next layers. In this study, we investigated a specific optical monitoring technique: polychromatic monitoring. This technique uses multiple wavelengths to monitor the layers’ deposition, instead of a unique wavelength for all layers such as conventional monochromatic monitoring. To evaluate the performance of this technique, we designed a numerical model to simulate the online monitoring signals during deposition, based on filter design and refractive index dispersion of the materials. Then, we developed an algorithm that applies several criteria on those simulated signals to automatically determine the most relevant wavelengths to monitor the filter layers - that is to say the ones that are expected to reduce layer thickness error during the deposition process. We also discuss the difficulties and limits when implementing such an approach, such as measured transmission errors or the critical instant for changing optical testglass. Afterwards, we experimentally tested these algorithms of determination of monitoring strategy on an error-sensitive multi-cavity bandpass filter.

Proceedings Article | 18 June 2024 Presentation

The choice of Deposition Equipment for challenging Interference Filter

Harro Hagedorn

Proceedings Volume PC13020, PC1302004 (2024) https://doi.org/10.1117/12.3023781

KEYWORDS: Interference filters, Sputter deposition, Physical vapor deposition, Magnetrons, Ion beams, Tunable filters, Deep ultraviolet

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Proceedings Article | 12 July 2023 Open Access

Comparison of monochromatic and broadband monitoring of optical interference filters

Janis Zideluns, Fabien Lemarchand, Detlef Arhilger, Harro Hagedorn, Julien Lumeau

Proceedings Volume 12777, 1277754 (2023) https://doi.org/10.1117/12.2690985

KEYWORDS: Optical sensing, Tunable filters, Transmittance, Optical filters, Glasses, Astronomical imaging, Design and modelling, Magnetrons, Sputter deposition, Thin films

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Proceedings Article | 17 March 2023 Paper

Production of dielectric filters with low defect levels for integrated optical devices

Stephan Mingels, Navas Kutty, Nicolaas Tack, Dries Bangels, Elias Janssens, Harro Hagedorn

Proceedings Volume 12424, 124241J (2023) https://doi.org/10.1117/12.2667774

KEYWORDS: Particles, Semiconducting wafers, Optical coatings, Optical filters, Semiconductors, Coating thickness, Dielectric filters, Vacuum chambers

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Proceedings Article | 12 September 2021 Presentation

Layer-by-layer adapted optical monitoring strategy of optical interference filters

Janis Zideluns, Julien Lumeau, Fabien Lemarchand, Detlef Arhilger, Harro Hagedorn

Proceedings Volume 11872, 118720P (2021) https://doi.org/10.1117/12.2597088

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Optical monitoring is a go to method for complex filters deposition; however, it can be easily shown that filter performance is dependent on monitoring strategy. When a non-quarter wave design needs to be deposited, usually one or minimal number of monitoring wavelengths is selected. This allows to use correction algorithms based on swing that are compatible with level-cut monitoring to a great extent. This approach has a significant drawback that it is very difficult to find one or few wavelengths that can be used for all layers of a complex filter. We present a different approach that relies on the selection of the best monitoring wavelength for each layer using pre-defined criteria that secure minimized thickness errors for each individual layer. Wavelength selection process uses several important criteria, such as monitoring wavelength sensitivity to errors in previous layers, transmittance evolution speed versus layer thickness growth, noise of measurement setup… We show that an additional important criteria is spectral resolution of the optical monitoring system and its impact on filter’s spectral response after each layer. Last, to ensure stable deposition we show that some precautions must be made to avoid false turning point detections. Using a binary approach for each criteria (pass or fail), monitoring wavelengths then can be selected automatically based on criteria defined above. In this work we demonstrate that such an approach can be implemented on stable deposition technique such as plasma assisted reactive magnetron sputtering (Bühler HELIOS machine) for different types of filters with various complexities. We illustrate our results for example on an 8-layer beamsplitter, a 37 layer D65 compensation filter, or a 100 layer custom shape spectral filter that are all very sensitive even to small thickness errors. Similar or better spectral performances are achieved compared with classical optical monitoring approaches but with an automatically determined optical monitoring strategy.

Proceedings Article | 11 June 2021 Open Access

Non-linearly variable filters for spectro-imaging systems

Thomas Begou, Frédéric Lemarquis, Antonin Moreau, Fabien Lemarchand, Holger Reus, Detlef Arhilger, Harro Hagedorn, Julien Lumeau

Proceedings Volume 11852, 118521B (2021) https://doi.org/10.1117/12.2599235

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Proceedings Article | 13 December 2020 Presentation

Magnetron sputtering technology for the fabrication of linearly variable filters

Thomas Bégou, Frédéric Lemarquis, Antonin Moreau, Fabien Lemarchand, Holger Reus, Detlef Arhilger, Harro Hagedorn, Julien Lumeau

Proceedings Volume 11451, 114511H (2020) https://doi.org/10.1117/12.2562192

KEYWORDS: Sputter deposition, Camera shutters, Linear filtering, Bandpass filters, Plasma, Optical filters, Imaging systems, Mirrors, Image filtering, Spectrophotometry

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Proceedings Article | 12 July 2019 Open Access

Linearly variable filters fabricated by magnetron sputtering technology

Thomas Bégou, Frédéric Lemarquis, Antonin Moreau, Fabien Lemarchand, Holger Reus, Detlef Arhilger, Harro Hagedorn, Julien Lumeau

Proceedings Volume 11180, 1118084 (2019) https://doi.org/10.1117/12.2536211

KEYWORDS: Optical filters, Bandpass filters, Sputter deposition, Linear filtering, Niobium, Camera shutters, Plasma, Imaging systems, Image filtering, Refractive index

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Proceedings Article | 16 November 2018 Paper

Production of high laser induced damage threshold mirror coatings using plasma ion assisted evaporation, plasma assisted reactive magnetron sputtering and ion beam sputtering

Alex Ribeaud, Jürgen Pistner, Harro Hagedorn, Matthew Brophy, Pete Kupinski, Jon Watson, Robert Hand

Proceedings Volume 10805, 1080511 (2018) https://doi.org/10.1117/12.2500354

KEYWORDS: Sputter deposition, Plasma, Silica, Ions, Planets, Ion beams, Optical coatings, Laser induced damage, Laser damage threshold, Mirrors

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Proceedings Article | 7 October 2015 Paper

High reflecting dielectric mirror coatings deposited with plasma assisted reactive magnetron sputtering

H. Hagedorn, J. Pistner

Proceedings Volume 9627, 96270Y (2015) https://doi.org/10.1117/12.2191350

KEYWORDS: Silica, Sputter deposition, Plasma, Dielectric mirrors, Absorption, Reflectivity, Transmittance, Scattering, Silicon, Dielectrics

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Proceedings Article | 23 September 2015 Paper

Advanced optical monitoring system using a new developed low noise wideband spectrometer system

Alfons Zöller, Detlef Arhilger, Michael Boos, Harro Hagedorn

Proceedings Volume 9627, 962712 (2015) https://doi.org/10.1117/12.2191269

KEYWORDS: Spectroscopy, Sensors, Control systems, Transmittance, Glasses, Detector arrays, Signal detection, Interference (communication), Optical coatings, Light

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Proceedings Article | 23 September 2015 Paper

High efficiency RF-plasma source with increased energy range

D. Arhilger, H. Hagedorn, H. Reus, A. Zöller

Proceedings Volume 9627, 96270O (2015) https://doi.org/10.1117/12.2191344

KEYWORDS: Silica, Ions, Plasma, Energy efficiency, Optical coatings, Refractive index, Argon, Neodymium, Scattering, Titanium dioxide

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Proceedings Article | 5 October 2011 Paper

Testglass changer for direct optical monitoring

A. Zoeller, H. Hagedorn, W. Weinrich, E. Wirth

Proceedings Volume 8168, 81681J (2011) https://doi.org/10.1117/12.896859

KEYWORDS: Transmittance, Coating, Multilayers, Glasses, Computer simulations, Optical testing, Optical filters, Crystal optics, Monochromators, Thin films

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Proceedings Article | 25 September 2008 Paper

Plasma ion-assisted deposition with radio frequency powered plasma sources

H. Hagedorn, M. Klosch, H. Reus, A. Zoeller

Proceedings Volume 7101, 710109 (2008) https://doi.org/10.1117/12.797818

KEYWORDS: Ions, Plasma, Optical coatings, Silica, Radio optics, Refractive index, Interference filters, Transmittance, Surface roughness, Titanium dioxide

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Proceedings Article | 25 September 2008 Paper

Computer simulation of coating processes with monochromatic monitoring

A. Zöller, M. Boos, H. Hagedorn, B. Romanov

Proceedings Volume 7101, 71010G (2008) https://doi.org/10.1117/12.797612

KEYWORDS: Coating, Computer simulations, Refractive index, Transmittance, Error analysis, Interference (communication), Multilayers, Linear filtering, Sputter deposition, Signal processing

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Proceedings Article | 25 September 2008 Paper

High performance notch filter coatings produced with PIAD and magnetron sputtering

M. Scherer, U. Schallenberg, H. Hagedorn, W. Lehnert, B. Romanov, A. Zoeller

Proceedings Volume 7101, 71010I (2008) https://doi.org/10.1117/12.797699

KEYWORDS: Linear filtering, Transmittance, Sputter deposition, Refractive index, Silica, Manufacturing, Absorbance, Optical coatings, Optical filters, Apodization

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Proceedings Article | 14 May 2007 Paper

Software tools for studying optical manufacturability with modern monochromatic monitoring devices

Alexander Tikhonravov, Michael Trubetskov, Jennifer Kruschwitz, Alfons Zoller, Harro Hagedorn, Boris Romanov, Michael Boos

Proceedings Volume 10316, 103161K (2007) https://doi.org/10.1117/12.718119

KEYWORDS: Optical coatings, Optics manufacturing, Coating, Mirrors, Transmittance, Error analysis, Refractive index, Optical engineering, Manufacturing, Optical fabrication

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Proceedings Article | 6 October 2005 Paper

Substantial progress in optical monitoring by intermittent measurement technique

A. Zoeller, M. Boos, R. Goetzelmann, H. Hagedorn, W. Klug

Proceedings Volume 5963, 59630D (2005) https://doi.org/10.1117/12.624865

KEYWORDS: Optical coatings, Transmittance, Bandpass filters, Sputter deposition, Polarizers, Glasses, Antireflective coatings, Linear filtering, Sensors, Thin films

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Proceedings Article | 5 October 2005 Paper

Oxide and fluoride coatings for the excimer wavelength 193nm

Rainer Götzelmann, Harro Hagedorn, Alfons Zöller, Alexei Kobiak, Werner Klug

Proceedings Volume 5963, 59630L (2005) https://doi.org/10.1117/12.625152

KEYWORDS: Reflectivity, Plasma, Oxides, Optical coatings, Deep ultraviolet, Mirrors, Aluminum, Silica, Thin film coatings, Absorption

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Proceedings Article | 5 October 2005 Paper

Innovative production of thin film laser components

Michael Scherer, Harro Hagedorn, Walter Lehnert, Juergen Pistner

Proceedings Volume 5963, 596319 (2005) https://doi.org/10.1117/12.625226

KEYWORDS: Mirrors, Sputter deposition, Thin films, Absorption, Silica, Refractive index, Laser components, Laser applications, Plasma, Multilayers

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Proceedings Article | 25 February 2004 Paper

Solutions for high-productivity high-performance coating systems

Harro Hagedorn

Proceedings Volume 5250, (2004) https://doi.org/10.1117/12.517388

KEYWORDS: Coating, Ions, Plasma, Sputter deposition, Control systems, Glasses, Coating equipment, Transmittance, Thin films, Interference filters

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Proceedings Article | 7 September 1999 Paper

UV coatings produced with plasma-ion-assisted deposition

Rainer Goetzelmann, Harro Hagedorn, Alfons Zoeller

Proceedings Volume 3738, (1999) https://doi.org/10.1117/12.360126

KEYWORDS: Transmittance, Plasma, Optical coatings, Absorption, Silica, Optical filters, Scattering, Multilayers, Reflectivity, Laser scattering

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Proceedings Article | 1 October 1997 Paper

Plasma-ion-assisted deposition: a powerful technology for the production of optical coatings

Alfons Zoeller, Rainer Goetzelmann, Harro Hagedorn, Werner Klug, K. Matl

Proceedings Volume 3133, (1997) https://doi.org/10.1117/12.290193

KEYWORDS: Coating, Plasma, Optical filters, Refractive index, Ions, Optical coatings, Transmittance, Temperature metrology, Glasses, Antireflective coatings

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