Conference Agenda

Topical Meetings and Sessions:

TOM 1 - Silicon Photonics and Guided-Wave Optics
TOM 2 - Computational, Adaptive and Freeform Optics
TOM 3 - Optical System Design, Tolerancing and Manufacturing
TOM 4 - Bio-Medical Optics
TOM 5 - Resonant Nanophotonics
TOM 6 - Optical Materials: crystals, thin films, organic molecules & polymers, syntheses, characterization and applications
TOM 7 - Thermal radiation and energy management
TOM 8 - Non-linear and Quantum Optics
TOM 9 - Opto-electronic Nanotechnologies and Complex Systems
TOM 10 - Frontiers in Optical Metrology
TOM 11 - Tapered optical fibers, from fundamental to applications
TOM 12 - Optofluidics
TOM 13 - Advances and Applications of Optics and Photonics
EU Project Session
Early Stage Researcher Session

More information on the Topical Meetings

Select a date or location to show only sessions at that day or location. Select a single session for a detailed view (with abstracts and downloads when you are logged in as a registered attendee). The rest of the TOM sessions, EU project session, tutorials, and Early Stage Researcher session will be updated soon. Thank you for your patience!

Session Overview
Location: B032
Ground floor, 99 seats
Date: Monday, 12/Sept/2022
1:00pm - 2:30pmTutorial Oliver Fähnle
Location: B032

Title: From Optical Design to Optical Fabrication and Photonics Systems Generation

Register for the tutorials here:

3:00pm - 4:30pmTutorial Rüdiger Paschotta
Location: B032

Title: Numerical modelling of fiber devices

Register for the tutorials here:

5:00pm - 6:30pmTutorial Thorlabs: Roozbeh Shokri
Location: B032

Date: Tuesday, 13/Sept/2022
11:30am - 1:00pmTOM3 S01: Optical System Design, Tolerancing and Manufacturing
Location: B032
Session Chair: Marco Hanft, Carl Zeiss AG, Germany
11:30am - 12:00pm
ID: 313 / TOM3 S01: 1
TOM 3 Optical System Design, Tolerancing and Manufacturing

Optical Design at The Age of AI

Simon Thibault

University Laval, Canada

Data-driven methods to assist lens design have recently begun to emerge; in particular, under the form of lens design extrapolation to find starting points (lenses and freeform reflective system). I proposed a trip over the years to better understand why the AI have been applied first to the starting point problems and where we are going in the future.

12:00pm - 12:15pm
ID: 180 / TOM3 S01: 2
TOM 3 Optical System Design, Tolerancing and Manufacturing

A systematic view of microscope objective design

Yueqian Zhang1, Herbert Gross2

1Carl Zeiss AG, Germany; 2Fraunhofer Institute for Applied Optics and Precision Engineering IOF, Germany

The correction of modern microscope objectives is not usually discussed in literature. We have reported a system review and summarized the design principles in a series of papers in 2019. Here we are introducing the systematic view of microscope objective design with an extension of the database till 2021. Furthermore, a systematic synthesis approach aided by AI will also be discussed.

12:15pm - 12:45pm
ID: 192 / TOM3 S01: 3
TOM 3 Optical System Design, Tolerancing and Manufacturing

Plasma jet assisted polishing of fused silica freeform optics

Thomas Arnold1,2, Georg Boehm2,3, Heike Mueller2, Martin Ehrhardt2, Klaus Zimmer2

1Technische Universität Dresden, Institut für Fertigungstechnik, Dresden, Germany; 2Leibniz Institute of Surface Engineering (IOM), Leipzig, Germany; 3Trionplas technologies, Leipzig, Germany

Atmospheric pressure plasma jet machining technology not only provides a flexible and efficient way to generate and correct optical freeform surfaces made of fused silica, it can also be applied as a surface smoothing or polishing technique. Thermal plasma jet treatment leads to softening and redistribution of the material. An accurate temperature regime during the process is inevitable to achieve a uniformly smoothed surface. The possibilities for in-process temperature control are demonstrated. Surface roughness values can be significantly reduced by a factor of 1000 depending on the initial roughness of the ground surface.

12:45pm - 1:00pm
ID: 315 / TOM3 S01: 4
TOM 3 Optical System Design, Tolerancing and Manufacturing

Neural Network for optical performance Estimation and advanced Lens Combination

Robert Brüning, Michael Verhoek, Uwe Lippmann

Fraunhofer Institute of Applied Optics and Precision Engineering IOF, Germany

We developed an algorithm to estimate the performance of an optical system based on the errors of its individual components. After a short training period with classical simulated systems, the performance evaluation for tolerancing could be accelerated by a factor of about three million. Additionally, we propose a probability-based sorting algorithm to combine individual, erroneous components in order to compensate for the tolerance budget within the system and increase the overall yield.

2:30pm - 4:00pmTOM3 S02: Optical System Design, Tolerancing and Manufacturing
Location: B032
Session Chair: Oliver Faehnle, OST – Ostschweizer Fachhochschule, Switzerland
2:30pm - 3:00pm
ID: 181 / TOM3 S02: 1
TOM 3 Optical System Design, Tolerancing and Manufacturing

Nautilus: The advent of large lens-based space telescopes

Daewook Kim1,2, Tom D. Milster1, Dániel Apai2,3

1James C. Wyant College of Optical Sciences, The University of Arizona, Tucson, AZ 85721, USA; 2Department of Astronomy and Steward Observatory, The University of Arizona, Tucson, AZ 85721, USA; 3Lunar and Planetary Laboratory, The University of Arizona, Tucson, AZ 85721, USA

One of the most profound and philosophically captivating foci of modern astronomy is studies of Earth-like exoplanets in search of life in the Universe. The paradigm-shifting investigation described here calls for a new type of space telescope that redefines the available light-collecting area in space, far beyond what is currently possible with the 6.5 m diameter James Webb Space Telescope. The Nautilus Space Observatory, which is enabled by multiple-order diffractive optics, is ushering in the advent of large space telescope lenses designed to search for biosignatures on a thousand exo-earths.

3:00pm - 3:15pm
ID: 127 / TOM3 S02: 2
TOM 3 Optical System Design, Tolerancing and Manufacturing

Planarization of lithium niobate surface using a thin film catalyst in pure water

Pho Van Bui1,2, Daisetsu Toh2, Masahiko Kanaoka1, Hiromi Okada1, Satoshi Matsuyama3, Kazuto Yamauchi2, Yasuhisa Sano2

1JTEC Corporation, Japan; 2Osaka University, Japan; 3Nagoya University, Japan

A catalytically assisted etching method, named Catalyst-Referred Etching (CARE) was applied to the planarization of Lithium Niobate (LN) surface, which is widely used for optical waveguides, optical modulators, piezoelectric applications. The study demonstrates that an atomically smooth surface with less than 0.1 nm root-mean-square roughness could be achieved on a LN substrate using a thin metal film and pure water as the catalyst and etching solution, respectively. All residual stress and surface damage could be removed completely thanks to the removal mechanism of CARE.

3:15pm - 3:30pm
ID: 205 / TOM3 S02: 3
TOM 3 Optical System Design, Tolerancing and Manufacturing

Concept, manufacturing and challenges of ultra-compact snapshot multispectral multi-aperture imaging systems

Martin Hubold, Johanna Karl, Robert Leitel, Norbert Danz, Robert Brüning

Fraunhofer IOF, Germany

Snapshot multispectral imaging is a rising non-invasive and contact-free analysis method and technology to discriminate or identify objects based on their spectral characteristics. We demonstrate a versatile system approach for compact and real-time capable snapshot cameras for the visible (VIS) and the near-infrared (NIR) or the short-wave infrared (SWIR) wavelength range based on a micro-optical multi-aperture system and various spectral filter approaches. In addition, the manufacturing, the calibration, and the limitations of the demonstration systems are described.

3:30pm - 3:45pm
ID: 317 / TOM3 S02: 4
TOM 3 Optical System Design, Tolerancing and Manufacturing

Mechanical Integration of a Prism-Grating-Prism-Assembly for the CO2M Mission

Andreas Kamm, Christian Scheffler, Thomas Peschel

Fraunhofer Institute of Applied Optics and Precision Engineering IOF, Germany

We developed and realized a mechanical integration concept of a prism-grating-prism-assembly for the CO2M mission. The mechanical design of the mounts relies on a kinematic mounting of the optical elements. Additional, ultra-light and blackened covers for stray light and disturbance light suppression are included. The complete assembly was investigated by extensive thermo-mechanical simulations to verify the stability of the mechanical design under operational, launch loads and test conditions.

3:45pm - 4:00pm
ID: 167 / TOM3 S02: 5
TOM 3 Optical System Design, Tolerancing and Manufacturing

Optimization of grinding processes on fused silica components using in-process vibrometry and dynamometer measurements

Sebastian Henkel1, Marcel Binder1, Jens Bliedtner1, Marco Fritzsche2, Abdulla Huseynov3, Franziska Schöneweck3, Sascha Greiner-Adam3, Jörg Flügge3, Edda Rädlein4

1Ernst-Abbe University of Applied Sciences Jena; 2Polytec GmbH; 3Batix Software GmbH; 4Technical University Ilmenau

The presented investigations deal with real-time evaluation and recording of vibrations and forces during a CNC grinding process, as well as the analysis and control of process influences on the surface quality of optical components. The experiments were carried out on a 5-axis CNC machine. Rapid subsequent analysis of the topography resulting from grinding is achieved with the aid of white light interferometry. The aim of the investigations is to reduce the surface deviations (roughness, mid-spatials, waviness) influenced by process factors. It is shown that the vibration data measured during the grinding process correlate to a high degree with the recorded topography data.

4:30pm - 6:00pmTOM3 S03: Optical System Design, Tolerancing and Manufacturing
Location: B032
Session Chair: Sven Schröder, Fraunhofer IOF, Germany
4:30pm - 5:00pm
ID: 303 / TOM3 S03: 1
TOM 3 Optical System Design, Tolerancing and Manufacturing

International and digital subsurface-damage-testing technologies laboratory

Jens Bliedtner1, Samson Frank1, Oliver Faehnle2, Heidi Cattaneo2

1Ernst-Abbe-University of Applied Sciences Jena, Germany; 2OST –Eastern Switzerland University of Applied Sciences Buchs, Switzerland

With the establishment of a versatile infrastructure for subsurface damages, a new interational laboratory has been established. For this purpose, researchers from the fields of optical metrology, optics technology, ophthalmology and computer science joined forces. A central research question and object of

object in the OpenLab are microcracks in optics

production, so-called subsurface damage. With the

ultra-high resolution and highly sensitive optical coherence

coherence tomography, a measuring principle based on white light principle based on white light interferometry, it will be possible to in glasses and ceramics with a resolution of 1 μm.

The laboratory is open to researchers and users to work together on topics related to SSD or to have measurement tasks carried out directly. The article presents the structure, the possibilities of cooperation and the goals of the open lab.

5:00pm - 5:15pm
ID: 309 / TOM3 S03: 2
TOM 3 Optical System Design, Tolerancing and Manufacturing

Improved production of large and multi-directional homogeneous optical glass: SCHOTT N-BK7® for challenging applications

Fabian Rupp, Ralf Jedamzik, Volker Dietrich, Uwe Petzold

SCHOTT AG, Germany

In many applications, the spatial refractive index variation – called homogeneity – within a measurement aperture either in one or two directions is important. Typical application examples are prisms in ultra-precision metrology with stability in multiple directions. Large lenses are used in artificial laser guide star systems for atmospheric correction in large telescopes. The challenge of enabling highest refractive index homogeneities requires tight control of all production steps from melting to hot forming and fine annealing. Large optical formats can be produced as singular castings in moulds up to 1.2 m in diameter and 250 mm thickness. Smaller formats are available as blocks produced in dimensions of approx. 250 x 250 x 180 mm3. A more economic and ecologic way is the production of continuous strips of glass up to approx. 500 mm width and 120 mm thickness. Recently SCHOTT has improved the homogeneity of these continuously produced jumbo strips significantly. Now homogeneity of up to H4 quality (2 ppm index maximum variation) can be provided on apertures up to approx. 900 mm x 500 mm. This paper gives an insight overview on the latest results and current state of this topic at the optical glass manufacturer SCHOTT.

5:15pm - 5:45pm
ID: 172 / TOM3 S03: 3
TOM 3 Optical System Design, Tolerancing and Manufacturing

Balancing your complexity budget

Sebastian Riese, Peter Zimmermann

LAYERTEC GmbH, Germany

The requirements for high-performance optics are continously increasing. This concerns optical requirements, e.g. for ultrafast optics, low-loss mirrors or high-power applications, and geometrical requirements alike, e.g. satisfying demanding spatial constraints or using free-form surfaces to reduce the number of required optics. As a result, substrate geometries and coatings grow more and more complex, posing challenges with respect to precision optics manufacturing, deposition technology and metrology as well as cost effectiveness.

LAYERTEC has addressed these kinds of challenges for more than 30 years. Proper communication of the required specifications is essential. Most importantly, the main properties of the optics have to be identified and mechanical, optical and coating engineering balanced accordingly. This is true for industry clients as well as research institutes, for high-volume fabrication or prototyping. Possible issues and lessons learned are presented.

5:45pm - 6:00pm
ID: 168 / TOM3 S03: 4
TOM 3 Optical System Design, Tolerancing and Manufacturing

Investigations on a novel process chain for manufacturing of freeform surfaces

Sebastian Henkel1, Christian Schulze1, Samson Frank1, Christoph Letsch1, Jens Bliedtner1, Thomas Arnold2, Heike Müller2, Edda Rädlein3

1Ernst-Abbe University of Applied Sciences Jena; 2Leibniz-Institut für Oberflächenmodifizierung e.V. (IOM); 3Technical University Ilmenau

Freeform optical surfaces have become increasingly important in recent years, as they can be used to construct optical assemblies with a reduced number of optical surfaces compared to systems without freeform surfaces, and thus optical systems can get more compact and lighter. However, the flexible and efficient production of precise optical freeform surfaces poses a major problem. This manifests itself in insufficient precision of the optics, long delivery times and high prices. It is shown, that ultrasonic grinding processes, combined with an ultra-fine grinding process and subsequent plasma jet polishing, are very well suited for the production of freeform optics and have a high technical and economic potential. Therefore, the aim is to validate an industrially suitable process chain based on this combination, in order to produce freeform optics of high accuracy (shape deviations <100 nm RMS) that can be manufactured in significantly fewer steps than before.


Date: Wednesday, 14/Sept/2022
9:00am - 10:30amTOM3 S04: Optical System Design, Tolerancing and Manufacturing
Location: B032
Session Chair: Marco Hanft, Carl Zeiss AG, Germany
9:00am - 9:30am
ID: 335 / TOM3 S04: 1
TOM 3 Optical System Design, Tolerancing and Manufacturing

Zoom lens first-order search tools: Monte Carlo vs particle swarm optimization

Julie Bentley, Jacob Sacks

University of Rochester

It is often easier (and faster) for a lens designer to adapt an existing design or known design form to a new problem. Very rarely do you need to go back to first-order thin lenses and/or invent a new form. However, the design of a new zoom lens is complex and typically requires a designer to “start from scratch”. Monte-Carlo (MC) searches have proven to be an effective way to characterize the first order solution space of zoom lenses, but MC simulations can take many hours/days to be completed, slowing down the design process. Particle swarm optimization (PSO) is an alternative optimization algorithm that mimics the hunting or foraging behaviors of a group of organisms. This paper compares the sets of solutions generated by MC and PSO methods, showing that PSO is capable of generating a diverse set of solutions that typically outperform the solutions generated by MC in a fraction of the time.

9:30am - 9:45am
ID: 185 / TOM3 S04: 2
TOM 3 Optical System Design, Tolerancing and Manufacturing

Ray transfer matrix for onion-type GRIN lenses

Veronica Lockett1, Rafael Navarro1, Jose Luis López2

1INMA, Consejo Superior de Investigaciones Científicas, Universidad de Zaragoza, Zaragoza, Spain; 2Universidad Pública de Navarra, Pamplona, Spain

We present the computation of an ABCD matrix for onion-type GRIN lenses. By applying a differential approximation of the layer thickness, the matrix product of a high number of matrices is synthetized into a single matrix where the elements are integrals. The difference between this ABCD matrix and a homogeneous lens matrix is one integration term in element C, which is the GRIN contribution to the lens power. In the case of the crystalline lens, the analytical approximation to the GRIN lens power provides an accurate and concise solution in terms of Gaussian hypergeometric functions.

9:45am - 10:00am
ID: 208 / TOM3 S04: 3
TOM 3 Optical System Design, Tolerancing and Manufacturing

Enabling photonic system integration by applying glass based microelectronic packaging approaches

Henning Schröder1, Wojciech Lewoczko-Adamczyk1, Daniel Weber2

1Fraunhofer IZM, Germany; 2Technische Universität Berlin

Advanced hybrid packaging technologies are used to enhance functionality of glass-based substrates featuring electrical, thermal and optical components including laser diodes, modulators, isolators, photonic integrated circuits, beam-splitters and micro lenses. Such glass-based substrates can be either thin glass layers on large panels containing optical waveguides or more mini-bench-like boards. Optical fiber interconnects, plugs, and electrical-optical integration platforms are used for higher level system integration. We discuss thin glass as a suitable base material for ion exchanged waveguide panels and interposers, precise glass structuring for posts and holders, electrical wiring and the related high precision assembly techniques.

10:00am - 10:15am
ID: 212 / TOM3 S04: 4
TOM 3 Optical System Design, Tolerancing and Manufacturing

Control of thermal emission for thermophotovoltaic systems

Daniela De Luca1,2, Antonio Caldarelli2,3, Eliana Gaudino2,3, Umar Farooq1,2, Marilena Musto2,3, Emiliano Di Gennaro1,2, Roberto Russo2

1Department of Physics, Università degli Studi di Napoli “Federico II”, 80125 Napoli, Italy; 2Deparment of Industrial Engineering, Università degli Studi di Napoli “Federico II”, 80125 Napoli, Italy; 3Consiglio Nazionale delle Ricerche, Istituto di Scienze Applicate e Sistemi Intelligenti, 80131 Napoli, Italy

Thermal emitters play a key role in controlling the thermal radiation emitted in thermophotovoltaic systems and in increasing their energy conversion efficiency. Here, we present different designs of emitters with spectrally selective properties, based on easy-to-fabricate multilayer structures and characterized by a sharp transition from high to low emissivity in the region of interest. Those structures make use of refractory materials to allow working at high operating temperatures and they can be easily customized to maximize the thermal emission in the region of the desired wavelengths.

10:15am - 10:30am
ID: 282 / TOM3 S04: 5
TOM 3 Optical System Design, Tolerancing and Manufacturing

Removing microdefects on glass surfaces using laser radiation

Kerstin Götze1, Jens Bliedtner1, Jürgen Bischoff1, Oliver Faehnle2, Michael Kahl2

1University of Applied Sciences Jena, Germany; 2OST – Eastern Switzerland University of Applied Sciences

Scratches and microdefects on glass surfaces significantly impair the optical and mechanical properties of optical components. They already occur during mechanical processing (shaping) and have to be removed in several specific processing steps. A process is presented with which scratches and microdefects can be removed by means of CO2 laser radiation.

2:30pm - 4:00pmTOM3 S05: Optical System Design, Tolerancing and Manufacturing
Location: B032
Session Chair: Daewook Kim, University of Arizona, United States of America
2:30pm - 3:00pm
ID: 358 / TOM3 S05: 1
TOM 3 Optical System Design, Tolerancing and Manufacturing

Current freeform metrology methods

Jessica DeGroote Nelson

Optimax, United States of America

Advancements in freeform manufacturing have been substantial in the last decade. The current limiting factor in the production of higher precision freeform manufacturing is metrology. This presentation will survey freeform metrology methods used in the industry today and highlight opportunities for future advancement in the field of freeform metrology to further higher precision freeforms.

3:00pm - 3:15pm
ID: 352 / TOM3 S05: 2
TOM 3 Optical System Design, Tolerancing and Manufacturing

The impact of surface specifications on thin film coatings and vice versa

Sven Schröder

Fraunhofer IOF, Germany

EDIT! Abstract of the paper

3:15pm - 3:30pm
ID: 189 / TOM3 S05: 3
TOM 3 Optical System Design, Tolerancing and Manufacturing

A brief application of material parameters to predict polishing rates for optical glasses

Michael Frederik Benisch1, Christian Trum1, Werner Bogner1, Oliver Fähnle2

1Deggendorf Institute of Technology, Germany; 2Eastern Switzerland University of Applied Sciences

This paper investigates the effects of material parameters of optical glasses on the polishing rate of these glasses. For this purpose, the material removal of various glasses was determined in laboratory tests under identical polishing conditions with respect to polishing pad and polishing suspension. The material removal was then evaluated for its dependence on material parameters. The goal of this paper is to derive a rule of thumb which allows an estimation of the material removal and the obtainable surface quality based on certain parameters of the workpiece material under comparable conditions. This rule of thumb can provide an initial insight into the polishability of a material and can be used to estimate polishing times and achievable surface qualities.

3:30pm - 3:45pm
ID: 284 / TOM3 S05: 4
TOM 3 Optical System Design, Tolerancing and Manufacturing

Ultra-short pulse laser-based fabrication process for lightweight structures in quartz glass applied for mirrors

David Bischof, Michael Kahl, Markus Michler

OST Eastern Switzerland University of Applied Sciences, Switzerland

In the following work a manufacturing process for light weight structures in Fused Silica is presented. Such structures can potentially be used for mirrors to decrease the mass by simultaneously ensuring high stiffness. This talk should give the audience the possibility to assess the selective laser etching technology for mechanical structures in the field of optical mirrors.

3:45pm - 4:00pm
ID: 311 / TOM3 S05: 5
TOM 3 Optical System Design, Tolerancing and Manufacturing

Development of a methodology for evaluating the process window of ductile machining for brittle-hard materials

Oliver Faehnle1, Thomas Liebrich2, Henrik Surberg1

1OST – Ostschweizer Fachhochschule, Switzerland; 2Rhysearch

This paper presents a standardized methodology for determining the process window for ductile machining of brittle materials. Its application for CaF2 is reported, identifying an optimized process window for single-point diamond turning on UPM machines by determining optimized process parameters.

4:30pm - 6:00pmTOM3 S06: Optical System Design, Tolerancing and Manufacturing
Location: B032
Session Chair: Jens Bliedtner, Ernst-Abbe-Uiversity of Applied Sciences Jena, Germany
4:30pm - 5:00pm
ID: 351 / TOM3 S06: 1
TOM 3 Optical System Design, Tolerancing and Manufacturing

Development of an aluminium reflecting telescope for small satellite

Okiharu Kirino

Crystal Optics Inc., Japan

A finishing technique by direct polishing of aluminium was investigated for low-cost manufacturing of reflecting telescopes for small satellites, the number of which is expected to increase in the future. By MRF polishing of aluminium alloy manufactured by the rapid solidification method, it was possible to achieve an ultra-precise finish equivalent to that of glass, with a surface roughness of about 1 nm Sa and a form accuracy of 100 nm PV or less.

5:00pm - 5:15pm
ID: 285 / TOM3 S06: 2
TOM 3 Optical System Design, Tolerancing and Manufacturing

Light Scattering from Contamination and Defects – Measurement, Analysis, and Modelling

Tobias Herffurth1, Alexander Bergner1,2, Sven Schröder1, Marcus Trost1

1Fraunhofer IOF, Germany; 2Institute of Applied Physics, FSU Jena, Germany

Light scattering induced by contamination and defects on optical components can quickly limit the component’s performance. Therefore, imperfection analysis and budgeting are mandatory - but also challenging tasks. On the other hand, imperfections can be elegantly characterized using efficient, robust and non-contact light scattering techniques. This will be demonstrated in this contribution for area covering measurement approaches using laboratory instruments with highest sensitivity as well as elaborated sensor systems that are best suited for extended freeform surfaces. Moreover, the measurement results are used to derive practical imperfection scattering data and models that serve as input to model and predict the imperfection induced scattering on optical system level.

5:15pm - 5:45pm
ID: 350 / TOM3 S06: 3
TOM 3 Optical System Design, Tolerancing and Manufacturing

Automated detection of scratch and dig on optical surfaces

Jean-Michel Asfour

DIOPTIC GmbH, Germany

The optical industry in Germany is closely associated with names such as Ernst Leitz, Moritz Hensoldt and Oskar Barnack, all of whom started their success stories as craft businesses in Wetzlar about 150 years ago. Manufacturing was and still is dominated by craftsmanship, as is the associated quality inspection and metrology. An important step here is the inspection of optical surfaces for cosmetic defects, an activity that is still predominantly performed visually by hand today. We demonstrate the challenges that an automated solution must meet and present a machine inspection solution that fulfils the requirements of the ISO standard and is superior to a manual visual inspection in terms of measurement uncertainty and costs. The system allows integration into a modern manufacturing environment, with the possibility to collect statistics of defect classes and thus optimize manufacturing processes, as well as the connection of the measured data to production databases.

5:45pm - 6:00pm
ID: 336 / TOM3 S06: 4
TOM 3 Optical System Design, Tolerancing and Manufacturing

Investigations on the production of optical freeforms applying the advanced wheel polishing process

Sebastian Stoebenau1, Igor Morozov1, Rafael Hild1, Sebastian Henkel2, Christian Schulze2, Christoph Letsch2, Samson Frank2, Jens Bliedtner2

1OptoTech Optikmaschinen GmbH, Germany; 2Ernst-Abbe University of Applied Sciences Jena, Germany

The growing interest in providing additional degrees of freedom to the design of high-end optical systems has led to an increased demand for freeform optical elements. The efficient fabrication of such elements requires a polishing process that provides high removal rates and a stable removal function while working with a relatively small spot size. Taking these constraints into consideration this paper focusses on the successful implementation of polishing processes applying the A-WPT (Advanced Wheel Polishing Tool) technology. Addressing the requirements regarding its removal characteristics as mentioned before, it represents an appropriate choice for providing an efficient pre-polishing as well as corrective polishing technique. In order to maintain perpendicularity towards the freeform surface to be polished, the A-WPT is run on a 5-axis simultaneous machining system. First investigations of the achieved surface accuracy after pre-polishing were carried out as well as an assessment of residual surface features within different spatial frequency regions. In addition, the polished surface is being checked for remaining SSD using an OCT technique.


Date: Thursday, 15/Sept/2022
8:30am - 10:00amTOM3 S07: Optical System Design, Tolerancing and Manufacturing
Location: B032
Session Chair: Sven Schröder, Fraunhofer IOF, Germany
8:30am - 9:00am
ID: 318 / TOM3 S07: 1
TOM 3 Optical System Design, Tolerancing and Manufacturing

Large metal mirrors for atmospheric telescopes

Guoyu Yu1, David Walker1,2,3, Hongyu Li1, Abdullah Shahjalal1, Trevor Walker4

1University of Huddersfield, United Kingdom; 2Zeeko Ltd, United Kingdom; 3University College London, United Kingdom; 4Thin Metal Films Ltd, United Kingdom

We are developing technologies in processing and metrology to fabricate a 1.4-meter aperture, aspherical surface Aluminium prototype mirror for Cherenkov Telescope Array. The aim is to fast process these large aperture mirrors at low cost. The technical development will ensure the high specifications on the surface quality. Different metrology methods including Swinging Arm Profilometry (SAP) and phase measuring deflectometry (PMD) are being developed. Recent results have shown very promising progress on these developments. We have excellent record in transferring our research results into industry. These cutting-edge technologies will be transferred to our industry partner to explore further developments.

9:00am - 9:15am
ID: 312 / TOM3 S07: 2
TOM 3 Optical System Design, Tolerancing and Manufacturing

Dynamic optimization of optical design process by means of producibility modulations

Olga Resnik1, Oliver Faehnle2, Yosi Arazi1

1JoYa Team; 2OST – Ostschweizer Fachhochschule, Switzerland

While optical design translates the application parameters of optical systems such as MTF and image resolution into a set of well-defined technical drawings, their manufacturability can only be assessed retrospectively, e.g. with PanDao. In this Paper, PanDao is being dynamically applied during the optical design process allowing to take producinbility aspects into account from the beginning on.

9:15am - 9:30am
ID: 239 / TOM3 S07: 3
TOM 3 Optical System Design, Tolerancing and Manufacturing

Optical methods for measuring the feature size of optical diffraction gratings with nano-meter accuracy and implementation of suitable feedback control loops

Thomas Flügel-Paul1, Martin Heusinger1, Kristin Gerold1, Adriana Szeghalmi1, Uwe Zeitner1,2

1Fraunhofer Institute For Applied Optics And Precision Engineering, Germany; 2Institute of Applied Physics, Friedrich-Schiller-Universität Jena, Germany

Surface relief diffraction gratings offer a high flexibility in their design and thus allow to synchronize their optical performance with the specific requirements of the underlying application. However, the accuracy and the specific control of the manufacturing processes are of vital importance. In this contribution, we present optical methods relying on white-light ellipsometry and how they can be exploited for the measurement of the critical dimensions of manufactured surface relief grating structures. We will furthermore present suitable processes (relying on atomic layer deposition) and how they are used in a feedback loop to control the grating’s feature sizes on the nanometer scale.

9:30am - 9:45am
ID: 331 / TOM3 S07: 4
TOM 3 Optical System Design, Tolerancing and Manufacturing

Advances in Robot Pre-Polishing platforms and mid-spatial removal technologies

Richard Freeman, Christopher King, Oliver Pakenham-Walsh, Kathryn Copson

Zeeko Ltd, United Kingdom

This paper documents the development of a Freeform Pre-Polisher that integrates Zeeko's well established Bonnet Polishing Technology, to a regular 6-Axis industrial Robot.

This platform is then used to test a novel new mid-spatial removal tool on different materials and the results of which are reported and discussed.