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Dr. Ing. Christine Wünsche

Centre for Applied Research

Institute for Precision Manufacturing and High-Frequency Technology (IPH)

Professor

T 105

09923/80108-405

Sortierung:
Lecture
  • Heiko Biskup
  • Rolf Rascher
  • Christine Wünsche

Poliermittelerprobung I.

In: Spectaris - 4. Treffen des Industriekonsortiums Seltene Erden

Technische Hochschule Deggendorf/Technologie Campus Teisnach Teisnach

  • 13.07.2011 (2011)
Lecture
  • Christian Schopf
  • Christine Wünsche

Herstellung von Präszisionsoptiken mit Formabweichung kleiner L/50.

In: 1. Wetzlarer Herbsttagung "Moderne Optikfertigung"

Wetzlar

  • 27.09.2011 (2011)
Lecture
  • Christian Schopf
  • Christine Wünsche

Projekt DuV. Posterpräsentation.

In: Internes Optikseminar der Forschungsgruppe Optik

Technische Hochschule Deggendorf/Technologie Campus Teisnach Teisnach

  • 2012 (2012)
Lecture
  • Christian Schopf
  • Christine Wünsche

Projekt 3P-Fertig. Posterpräsentation.

In: Internes Optikseminar der Forschungsgruppe Optik

Technische Hochschule Deggendorf/Technologie Campus Teisnach Teisnach

  • 2012 (2012)
Lecture
  • Heiko Biskup
  • Rolf Rascher
  • Christine Wünsche

Poliermittelerprobung II.

In: Spectaris - 6. Treffen des Industriekonsortiums Seltene Erden

Mainz

  • 23.02.2012 (2012)
Lecture
  • Heiko Biskup
  • Rolf Rascher
  • Christine Wünsche

Laserdiffraktometrie zur Charakterisierung von Korngrößen und deren Verteilung in Poliermitteln.

In: 5. Optikseminar

Technische Hochschule Deggendorf/Technologie Campus Teisnach Teisnach

  • 30.07.2012 (2012)
Lecture
  • Heiko Biskup
  • Rolf Rascher
  • Christine Wünsche

Laserdiffraktometrie - Korngrößenverteilung in Poliermitteln. Posterbeitrag.

In: 5. Optikseminar

Technische Hochschule Deggendorf/Technologie Campus Teisnach Teisnach

  • 30.07.2012 (2012)
Lecture
  • Paul Schötz
  • Johannes Liebl
  • Rolf Rascher
  • Christine Wünsche
  • Engelbert Hofbauer
  • Karlheinz Penzkofer

Metrology at Technologie Campus Teisnach.

In: 8th Workshop Asphere Metrology

Physikalisch-Technische Bundesanstalt (PTB)/Kompetenzzentrum Ultrapräzise Oberflächenbearbeitung e.V. Braunschweig

  • 12.-13.11.2012 (2012)
Contribution
  • Roland Maurer
  • Florian Schneider
  • Christine Wünsche
  • Rolf Rascher

Calculation of the reference surface error by analyzing a multiple set of sub-measurements.

In: SPIE Optics + Photonics 2013, Optical Manufacturing and Testing X, volume 8838.

  • (2013)

DOI: 10.1117/12.2024003

show abstract

In the field of precision optics the interferometry is the most applied measurement method to test spherical and flat objects. In principle, a standard interferometer setup is limited to these surface geometries, but interferometric systems may be modified with the aid of CGH’s or the stitching technology. As a consequence aspherical shapes and even freeform optics are measurable up to a certain extent. In an interferometric measurement the measured variable is the optical path difference (OPD) between the reference wave and the test wave. Based on the detected OPD the surface error of the test object is calculated by phase shifting methods for instance. It is evident, that the error from the reference surface affects the determination of the test object surface error. One option to face this problem is the calibration of the system prior to the measurement. For this the determination of the reference surface error may be realized with the aid of a two sphere test or a random ball test e.g. [1]. In the well-known SSI-technology from QED technologies the reference surface error is calculated on the basis of the sub-measurements. Due to the self-calibrating nature of the QED stitching principle [2-4] a calibration of the system prior to the measurement is not necessary. The University of Applied Sciences Deggendorf has implemented a similar algorithm to estimate the reference wave front error, or to be exact the error of the whole optical system, based on a multiple set of sub-measurements. This paper describes the applied algorithm in detail and discusses the results. To verify the implemented tool the results are compared to the outcomes of the QED stitching software. © (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Lecture
  • Florian Schneider
  • Markus Schinhärl
  • Christine Wünsche
  • et al.

3D Scale - A system to reduce and compensate the influence of multiple axis errors of rotational axes.

In: SPIE Photonics West, Optoelectronic Materials and Devices, SPIE 2013

  • 2013 (2013)
Journal article
  • Christian Schopf
  • Rolf Rascher
  • Christine Wünsche

Rauhigkeitsmessungen an großen und schwer zugänglichen Bauteilen.

In: MM Industriemagazin-Maschinenmarkt pg. 40-41

  • (2013)
Contribution
  • Florian Schneider
  • Roland Maurer
  • Christine Wünsche
  • R. Stamp
  • G. Smith

Analysis of three different measurement strategies carried out with the TII-3D coordinate measurement system.

In: SPIE Optics + Photonics 2013, Optical Engineering + Applications.

  • (2013)

DOI: 10.1117/12.2024001

show abstract

Together with the group of interferometry based systems, coordinate measurement machines are an essential part of the metrology in the modern optical industry. Coordinate measurement machines commonly consist of a multi axes framework. They are designed to operate in a defined three dimensional work zone, where every possible point can be reached by the measurement tool tip. This basic design principle leads to some interdependent challenges. A detailed measurement result needs a large amount of measurement points to detect even minor irregularities and short-wave errors. However, a rising of the amount of measurement points increases the corresponding measurement time analogous. On the other hand, the extended operation time increases the access of undesired thermal and dynamic influences, which cause multiple errors to the measurement result. Furthermore, modern production processes need rapid metrology systems to aid the machining time. This paper discusses results obtained by operating with three different measurements in order to find an agreement between speed and certainty of the coordinate measurement machine. The topographic coordinate measurement system TII- 3D had been re-developed at the University of Applied Sciences Deggendorf in the laboratory of optical Engineering and it is equipped with three different measurement strategies. The first mode, the Track-Mode operates in concentric circles on top of the surface of the object to be measured. The Spiral-Mode measures along a dynamic moveable spiral line and the Section-Mode produces multiple cross-sections. © (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Lecture
  • M. Willert-Porada
  • Thorsten Gerdes
  • A. Rosin
  • A. Saberi
  • A. Füller
  • Rolf Rascher
  • Christine Wünsche

Flexiplant: schmelzebasierte kontinuierliche Herstellung von low TG-Glas-Preformen (mittels Minimeltertechnologie).

In: 87. Glastechnische Tagung

HVG-DGG: Service und Forschung für die Glasherstellung Bremen

  • 27.-29.05.2013 (2013)
Contribution
  • Roland Maurer
  • Heiko Biskup
  • Christian J. Trum
  • Rolf Rascher
  • Christine Wünsche

Determination of a suitable parameter field for the active fluid jet polishing process.

In: Optifab 2013. (Proceedings of SPIE)

  • Eds.:
  • J. Bentley
  • M. Pfaff

  • (2013)

DOI: 10.1117/12.2028752

show abstract

In 2012 a well-known company in the field of high precision optics assigned the University of Applied Sciences Deggendorf to determine a suitable parameter field for the active fluid jet polishing (AFJP) process in order to reach a surface accuracy of at least lambda / 5. The active fluid jet polishing is a relatively new and an affordable sub-aperture polishing process. For a fast and precise identification of the parameter field a considered design of experiment is necessary. The available control variables were the rotational speed of the nozzle, the distance between the test object and the jet, the feed rate, the material of the pin inside the nozzle and the material of the test object itself. In order to reach a significant data density on the one hand and to minimize the number of test runs on the other hand a meander shaped tool path was chosen. At each blank nine paths had been driven whereby at each path another parameter combination was picked. Thus with only one test object nine parameter settings may be evaluated. For the automatized analysis of the tracks a software tool was developed. The software evaluates ten sections which orthogonally intersect the nine tracks on the test-lens. The significant measurement parameters per section are the width and the height of each path as well as the surface roughness within the polished tracks. With the aid of these parameters and further statistical evaluations a suitable parameter field for the goal to find a constant and predictable removal spot was determined. Furthermore up to now over 60 test runs have been successfully finished with nine parameter combinations in each case. As a consequence a test evaluation by hand would be very time-consuming and the software facilitates it dramatically.
Lecture
  • S. Draxinger
  • Christine Wünsche
  • Rolf Rascher

Subaperture-polishing with variable spots.

In: Renewable Energy and the Environment, Freeform Optics (Freeform)

The Optical Society of America (OSA) Tucson, AZ, USA

  • 03.-06.11.2013 (2013)
Journal article
  • Johannes Liebl
  • Heiko Biskup
  • S. Draxinger
  • Rolf Rascher
  • Christine Wünsche

Process developement fort the reproducible roughness measurement of optical surfaces using white light interferometry.

In: International Journal of Metrology and Quality Engineering (EDP Sciences) vol. 5 pg. 29-35

  • (2014)

Contribution
  • O. Fähnle
  • E. Langenbach
  • F. Frost
  • A. Schindler
  • Heiko Biskup
  • Johannes Liebl
  • Christine Wünsche
  • Rolf Rascher

Generation and field testing of roughness reference samples for industrial testing of surface roughness levels below 0.5nm Sq.

In: Proceedings of EOSAM 2014 (European Optical Society Annual Meeting) [Sep 15-19 2014, Berlin, Germany]. pg. 216-218

  • (2014)
Lecture
  • Christine Wünsche

Automatisierte Sauberkeitskontrolle.

In: Spectaris Seminar "Moderne Messtechniken bei Fertigung von Präzisionsoptiken"

Wetzlar

  • 19.02.2014 (2014)
Lecture
  • Thorsten Gerdes
  • K. Kyrgyzbayev
  • A. Rosin
  • A. Saberi
  • A. Füller
  • Rolf Rascher
  • Christine Wünsche

Aims for the development of new optical glass materials.

In: 1st European Seminar on Precision Optics Manufacturing

Technische Hochschule Deggendorf/Technologie Campus Teisnach Teisnach

  • 01.-02.04.2014 (2014)
Lecture
  • Christine Wünsche

Challenges in Production Technologies in producing surfaces in a quality of Lambda/50.

In: 1st European Seminar on Precision Optics Manufacturing

Technische Hochschule Deggendorf/Technologie Campus Teisnach Teisnach

  • 01.-02.04.2014 (2014)
Lecture
  • S. Draxinger
  • Christian J. Trum
  • Heiko Biskup
  • Christine Wünsche
  • Rolf Rascher

Active Fluid Jet Polishing - Behaviour on Different Materials.

In: Optical Fabrication and Testing (OF&T)

The Optical Society of America (OSA) Kohala Coast, HI, USA

  • 22.-26.06.2014 (2014)
Lecture
  • Patrick Schäfer
  • Christine Wünsche
  • Rolf Rascher

Quantification of synthetic lens surface characteristics by an optical measurement system as stylus instrument.

In: Optics and Measurement International Conference 2014

Liberec, Tschechische Republik

  • 07.-10.10.2014 (2014)
Contribution
  • Patrick Schäfer
  • Christine Wünsche
  • Rolf Rascher

Quantification of synthetic lens surface characteristics by an optical measurement system as stylus instrument.

In: Proceedings of SPIE 9442. Optics and Measurement International Conference 2014 (07.-10.10.2014, Liberec, Tschechische Republik) pg. 944219

  • (2015)
Contribution
  • Robert Schneider
  • Christian J. Trum

Hexapod as primary kinematic system for applications in the optic industry.

In: Proceedings of SPIE 10009 (Third European Seminar on Precision Optics Manufacturing, 100090Y [April 12th 2016, Teisnach]).

  • Eds.:
  • Christian Schopf
  • O. Fähnle
  • Rolf Rascher
  • Christine Wünsche

  • (2016)

DOI: 10.1117/12.2235400

Contribution
  • Manon Schilke
  • Johannes Liebl
  • Christine Wünsche

Surface reconstruction by using Zernike polynomials.

In: Proceedings of SPIE 10009 (Third European Seminar on Precision Optics Manufacturing, 100090Y [April 12th 2016, Teisnach]).

  • Eds.:
  • Christian Schopf
  • O. Fähnle
  • Rolf Rascher
  • Christine Wünsche

  • (2016)

DOI: 10.1117/12.2236305

show abstract

The development of high precision methods for the measurement of plano surfaces became of increasing importance over the last years. Recently accuracies in sub-nanometer range have been achieved on samples up to one meter in diameter. The used measurement method was based on direct deflectometry. The main part of the system was an electronic autocollimator measuring local angular displacements on defined traces along the surface of the plano lens. To stabilize the optical path a pentaprism was used. The measurement accuracy of a similar system was evaluated at the Technologie Campus Teisnach. The used system delivered twenty measurement spots along the profile on one diameter. Four diameters were measured at every 45 degrees. An evaluation algorithm was developed to model the complete threedimensional surface out of a small amount of measurement points. Within this modelling Zernike polynomials were used to reconstruct the surface topography. Two different approaches in using the hierarchy of the polynomials were compared. At first a reference surface was created by rotating a symmetrical averaged curve of all measured profiles. On the residuals of the original measurements to the symmetrical averaged curve a serial development of the error surface was applied with the help of Zernike polynomials. Different order of Zernike terms were tested because we saw a big influence on the result. This surface was added to the reference surface. The results of the two different approaches were compared. To enable us to compare the results of this measurement method to interferometric and optical 3Dprofilometric measurements the data was converted to xyz-format. © (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Contribution
  • Christian Vogt
  • S. Sinzinger
  • Martin Rohrbacher
  • Rolf Rascher

Prediction of grinding tool wear and lifetime by using a test bench.

In: Proceedings of SPIE 10009 (Third European Seminar on Precision Optics Manufacturing, 100090Y [April 12th 2016, Teisnach]).

  • Eds.:
  • Christian Schopf
  • O. Fähnle
  • Rolf Rascher
  • Christine Wünsche

  • (2016)
Contribution
  • Engelbert Hofbauer
  • Rolf Rascher
  • Manon Schilke
  • Johannes Liebl
  • J.-P. Richters

Deflectometric acquisition of large optical surfaces (DaOS) using a new physical measurement principle: vignetting field stop procedure.

In: Proceedings of SPIE 10009 (Third European Seminar on Precision Optics Manufacturing, 100090Y [April 12th 2016, Teisnach]).

  • Eds.:
  • Christian Schopf
  • O. Fähnle
  • Rolf Rascher
  • Christine Wünsche

  • (2016)

DOI: 10.1117/12.2236134

Contribution
  • Sebastian Sitzberger
  • Rolf Rascher

An investigation on the efficiency of the manufacturing of components in precision optics.

In: Proceedings of SPIE 10009 (Third European Seminar on Precision Optics Manufacturing, 100090Y [April 12th 2016, Teisnach]).

  • Eds.:
  • Christian Schopf
  • O. Fähnle
  • Rolf Rascher
  • Christine Wünsche

  • (2016)

DOI: 10.1117/12.2236137

show abstract

By adaption and coordination of successive process steps the efficiency of producing optics can be improved. In the beginning of this investigation, the focus is on two crucial process steps of the optical manufacturing process. First, there is the optical and mechanical design of the optical part and system. In this context, it is important to consider what modifications compared to the current standard design are possible respectively useful. Thus, the modifications will only concentrate on parts of the optic that do not interfere with the optical functionality. Furthermore in this part of the study the main aspect is the clamping situation of the optical part in a holder or an optical system. It will be discussed, whether it is useful to add special clamping surfaces respectively a clamping flange in contrast to the standard design. The faultless functioning of the optics has always first priority. Second, the manufacturing process itself has a great number of single steps. Therefore, a main part of the research is the investigation of current clamping situations in optics manufacturing, with prospect to improve them in order to work perfectly with the design modifications, as mentioned above. This part of the investigation focuses on the clamping system for the lens on each machine necessary for manufacturing. In the scope of this paper the authors want to summarize characteristics and deficits of current clamping systems and workpiece mounts and give a prospect of the following course of action. © (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Contribution
  • Johannes Liebl
  • Horst Linthe
  • Sebastian Sitzberger
  • Rolf Rascher

Interferometric measurement of highly accurate flat surfaces.

In: Proceedings of SPIE 10009 (Third European Seminar on Precision Optics Manufacturing, 100090Y [April 12th 2016, Teisnach]).

  • Eds.:
  • Christian Schopf
  • O. Fähnle
  • Rolf Rascher
  • Christine Wünsche

  • (2016)

DOI: 10.1117/12.2235525

show abstract

The most important part in manufacturing precision optics is a reliable measurement procedure which provides results a few times more accurate than the quality to be produced. In general two specific values are important, the repeatability of several measurements which are done in a row and the absolute accuracy which is mostly defined by the systematical error of the measurement device. The repeatability can be improved relatively simple, by increasing the number of measurements and a following averaging step. To increase the absolute accuracy of a measurement device in the field of precision optics is far more challenging. In this paper several interferometer absolute testing methods to measure flat surfaces are compared. The main objective was to name a value for the achievable accuracy. Therefor four different methods were analyzed: 1. The three flat test, a method which is already used several decades to determine the quality of a flat surface. As a result, two absolute measured profiles, horizontal and vertical, can be calculated. 2. The multi rotation test, an extension of the classical three flat test. The big advantage of this method is a fully three dimensional map of the systematical error. 3. The systematical error calculated by the SSI-A. Hereby several subapertures are measured over the whole surface. The redundant information’s of the overlapping regions can be used to calculate the systematical error of the system. 4. The rotation of the transmission flat relatively to the interferometer. Thereby the rotation unsymmetrical errors can be calculated and subtracted. © (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Contribution
  • Gerald Fütterer

From Holographic displays to Volume Gratings and Off-Axis Parabolic Mirrors.

In: Proceedings of SPIE 10009 (Third European Seminar on Precision Optics Manufacturing, 100090Y [April 12th 2016, Teisnach]). pg. 1000912

  • Eds.:
  • Christian Schopf
  • O. Fähnle
  • Rolf Rascher
  • Christine Wünsche

  • (2016)

DOI: 10.1117/12.2245183

show abstract

An important chain link in modeling of three dimensional data (3D data), 3D prototyping, CAD-CAM, computerintegrated manufacturing (CIM), PC gaming, global 3D teleconferencing, future e-commerce, product advertisement and mobile infotainment is the visualization of 3D data and 3D objects. On the one hand, there is an increasing demand for 3D displays providing natural three dimensional viewing experience, but on the other hand there is a lack of available 3D displays capable of generating all depth cues. Available state of the art 3D displays can provide only a few depth cues and a very limited 3D experience. This is due to the inherent physical limits of the different approaches used. Holographic displays, for instance based on space bandwidth limited wave segment reconstruction, can provide all depth cues and a large viewing volume. They can provide satisfying 3D visualization. But still they are not available. Thick hologram gratings 1, which also can be referred to as Bragg diffraction based volume gratings, are key components, which enable small form factor holographic 3D displays. Manufacturing large, display size Bragg diffraction based volume gratings is challenging. Collimators are key components within interference lithographic exposure setups. Using off-axis parabolic mirrors (OAPM) as collimating optical elements enables the generation of exact plane waves by using a single reflective surface. Thus, off-axis parabolic mirrors are preferred in order to realize the collimation of large wave fronts. The surface roughness has to be very low. The relationship between holographic 3D displays and specific requirements, which have to be taken into account when manufacturing off-axis parabolic mirrors, will be presented. © (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Contribution
  • Christian J. Trum
  • Rolf Rascher

Improving efficiency of chemo-mechanical polishing processes by systematic selection and conditioning of the polishing suspension.

In: Proceedings of SPIE 10009 (Third European Seminar on Precision Optics Manufacturing, 100090Y [April 12th 2016, Teisnach]).

  • Eds.:
  • Christian Schopf
  • O. Fähnle
  • Rolf Rascher
  • Christine Wünsche

  • (2016)

DOI: 10.1117/12.2236000

show abstract

During design of optical systems or individual components, customers and designers already predetermine the way through production and the necessary resources. They define the tolerances that are required for their application like shape, micro-roughness and cleanliness, as well as the glass material that is necessary for the targeted optical effect. By the tolerances, they have also an influence on the manufacturer and his decisions on the production environment, measurement technology and the process chain that in his opinion is necessary to meet the specification. In most cases the type of polishing suspension and its parameters are also predetermined by the use of central polishing supply systems. With this paper, the authors want to give a prospect of a currently running research with the aim of increasing the efficiency of chemo-mechanical polishing processes by a systematic selection and conditioning of the polishing suspension. They want to show that small amounts of well-conditioned and stabilized polishing suspension could be a tool to improve the efficiency in CMP processes under the influence of the global trend to products that are more individual and down to one piece flow production. Main parts of this research are the identification of influences of polishing suspensions on the quality criteria of optical components and the creation of a method to find well-working suspension parameters in a deterministic and reproducible way. © (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Lecture
  • Rolf Rascher
  • Christine Wünsche
  • Christian Schopf

Aspects in laser polishing of precision optical components.

In: LaP 2016 - 2nd Conference on Laser Polishing

Aachen

  • 26.-27.04.2016 (2016)
Contribution
  • Alexander Haberl
  • Rolf Rascher

Yet one more dwell time algorithm.

In: Proceedings of SPIE 10326 (Fourth European Seminar on Precision Optics Manufacturing, 1032601 [April 4th-5th 2017, Teisnach]). pg. 1032606

  • Eds.:
  • Christian Schopf
  • O. Fähnle
  • Rolf Rascher
  • Christine Wünsche

  • (2017)

DOI: 10.1117/12.2270540

Contribution
  • P. Rinck
  • Sebastian Sitzberger
  • M. Zaeh

Actuator design for vibration assisted machining of high performance materials with ultrasonically modulated cutting speed.

In: Proceedings of SPIE 10326 (Fourth European Seminar on Precision Optics Manufacturing, 1032601 [April 4th-5th 2017, Teisnach]). pg. 103260C

  • Eds.:
  • Christian Schopf
  • O. Fähnle
  • Rolf Rascher
  • Christine Wünsche

  • (2017)

DOI: 10.1117/12.2272133

Contribution
  • Josef Stettmer

Process optimization at small and medium-sized enterprises: production of small and medium-sized batches.

In: Proceedings of SPIE 10326 (Fourth European Seminar on Precision Optics Manufacturing, 1032601 [April 4th-5th 2017, Teisnach]). pg. 103260P

  • Eds.:
  • Christian Schopf
  • O. Fähnle
  • Rolf Rascher
  • Christine Wünsche

  • (2017)

DOI: 10.1117/12.2275028

Contribution
  • Gerald Fütterer

Polarization-Fizeau interferometer enabling phase measurement with reduced uncertainty.

In: Proceedings of SPIE 10326 (Fourth European Seminar on Precision Optics Manufacturing, 1032601 [April 4th-5th 2017, Teisnach]). pg. 103260B

  • Eds.:
  • Christian Schopf
  • O. Fähnle
  • Rolf Rascher
  • Christine Wünsche

  • (2017)

DOI: 10.1117/12.2272001

Contribution
  • Christian J. Trum
  • Sebastian Sitzberger
  • Rolf Rascher

Advanced method for the characterization of polishing suspensions.

In: Proceedings of SPIE 10326 (Fourth European Seminar on Precision Optics Manufacturing, 1032601 [April 4th-5th 2017, Teisnach]). pg. 103260I

  • Eds.:
  • Christian Schopf
  • O. Fähnle
  • Rolf Rascher
  • Christine Wünsche

  • (2017)

DOI: 10.1117/12.2272431

Contribution
  • Christian Vogt
  • O. Fähnle
  • Rolf Rascher

Force-controlled analysis tool for optimization of precision CNC grinding processes.

In: Proceedings of SPIE 10326 (Fourth European Seminar on Precision Optics Manufacturing, 1032601 [April 4th-5th 2017, Teisnach]). pg. 103260M

  • Eds.:
  • Christian Schopf
  • O. Fähnle
  • Rolf Rascher
  • Christine Wünsche

  • (2017)

DOI: 10.1117/12.2272713

Contribution
  • Engelbert Hofbauer
  • Rolf Rascher
  • Felix Friedke
  • R. Kometer

Resolution, measurement errors and uncertainties on deflectometric acquisition of large optical surfaces "DaOS".

In: Proceedings of SPIE 10326 (Fourth European Seminar on Precision Optics Manufacturing, 1032601 [April 4th-5th 2017, Teisnach]). pg. 1032603

  • Eds.:
  • Christian Schopf
  • O. Fähnle
  • Rolf Rascher
  • Christine Wünsche

  • (2017)

DOI: 10.1117/12.2267513

Contribution
  • Sebastian Sitzberger
  • Christian J. Trum
  • Rolf Rascher

Analysis of the influence of the workpiece self-weight in precision optics manufacturing using FEM simulation.

In: Proceedings of SPIE 10326 (Fourth European Seminar on Precision Optics Manufacturing, 1032601 [April 4th-5th 2017, Teisnach]). pg. 103260O

  • Eds.:
  • Christian Schopf
  • O. Fähnle
  • Rolf Rascher
  • Christine Wünsche

  • (2017)

DOI: 10.1117/12.2273023

Contribution
  • Robert Schneider
  • Alexander Haberl
  • Rolf Rascher

Polishing tool and the resulting TIF for three variable machine parameters as input for the removal simulation.

In: Proceedings of SPIE 10326 (Fourth European Seminar on Precision Optics Manufacturing, 1032601 [April 4th-5th 2017, Teisnach]). pg. 1032602

  • Eds.:
  • Christian Schopf
  • O. Fähnle
  • Rolf Rascher
  • Christine Wünsche

  • (2017)

DOI: 10.1117/12.2267415

Contribution
  • Jessica Stelzl
  • Christine Wünsche
  • S. Höfer

Processing of a new nonlinear optical crystal for continuous wave UV-laser applications.

In: Proceedings of SPIE 11171 (Sixth European Seminar on Precision Optics Manufacturing, 1117101 [9-10 April 2019, Teisnach]). pg. 111710H1-111710H4

  • Eds.:
  • Christian Schopf
  • Rolf Rascher

Bellingham, WA, USA

  • (2019)

DOI: 10.1117/12.2528140

show abstract

Lasers have been known for a long time and are used in a wide variety of fields such as industrial and material processing or measuring and control technology. A new application is being tested which aims to use continuous wave UV-lasers in metrology. For this application a nonlinear optical crystal is needed. Its processing is developed in a two-year project at the Institute for Precision Manufacturing and High-Frequency Technology of Deggendorf Institute of Technology. The crucial factor for the full optical performance in the UV range is the low roughness of the crystal surface, as it is installed between two prisms and the contactability between them should be ensured. In China, a nonlinear crystal that meets the requirements has already been designed and a production process for the raw crystal has been established. However, since the production of optically homogenous crystals has proven to be difficult, the availability of such is very limited. For this reason, a reference material with similar hardness and material behaviour is used in the process development in order not to be limited in the number of trials. It is important to be able to transfer the results from the reference material in an analogous way to the original crystal. One challenge of the project lies in the crystal thickness, since only a maximum thickness of three millimetres can be achieved for the purest form of the crystal required in the application. Therefore, it is important to handle the material sparingly during the process. In addition, the small dimensions of about ten to five millimetres and the brittleness of the material pose a problem. The goal of the project will be to develop a process that can circumvent all these problems so that small roughness of the crystal can be achieved by precision polishing.
Contribution
  • Emilio Zambrano
  • Christine Wünsche
  • S. Mechold
  • S. Herr

Cleaning effects in optical layers: error characteristics and analysis methods.

In: Proceedings of SPIE 11171 (Sixth European Seminar on Precision Optics Manufacturing, 1117101 [9-10 April 2019, Teisnach]). pg. 111710F1-111710F9

  • Eds.:
  • Christian Schopf
  • Rolf Rascher

Bellingham, WA, USA

  • (2019)

DOI: 10.1117/12.2527974

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In the course of the ever-increasing demand of high-performance optical components, dielectric coating processes are the key technology for the refinement of optics, ensuring their functionality. These optics are based on optical interference coatings, which are formed by a layer stack of alternating transparent single layers of high and low refractive index material. Assuming that turbidity as well as defects embedded in coatings are considered as a primary factor limiting the quality of optical coatings, the level of cleaning the substrates before coating has to be extremely high. Particular importance is attached to the interface between the layer stack and the substrate, especially to the interaction during the transition from the glass surface to the coating during the manufacturing process. This interaction is assumed to be caused by polishing, by corrosion during storage time or by effects during cleaning of the substrate before coating. Thus, it is necessary to characterize each type of defect and to define which technique is adequate to analyze each one of them efficiently. The project aims to raise the awareness and knowledge in terms of what happens during the coating process and, in particular, to understand the physical processes at the substrate during the manufacturing process. After analyzing the material flow, first focus was set on the cleaning procedure. It is assumed that one of the main influences on defects in the interface is the chemical cleaning. Chemical reactions on the surface of the glass substrate may occur due to additional effects of external components and elevated temperature in the washing basins.
Contribution
  • Jessica Stelzl
  • Christine Wünsche
  • S. Höfer

Influencing factors for a continuous wave UV-laser component.

In: Proceedings of SPIE 11478 (Seventh European Seminar on Precision Optics Manufacturing [8 July 2020; Teisnach]). pg. 114780C

  • Eds.:
  • Alexander Haberl
  • O. Fähnle
  • Gerald Fütterer
  • Rolf Rascher

Bellingham, WA, USA

  • (2020)

DOI: 10.1117/12.2564916

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During the development of an optical system, one comes to the point where you have to build the optically active element into a mechanical device that becomes part of the system. At this point you come across the well-known question that it is not only necessary to consider and ensure the quality of the individual element. It is also important to look at the entire component in order to identify potential influencing factors on the performance of the optical system. At the beginning of a two-year project at Technologiecampus Teisnach the polishing process of a nonlinear crystal as the crucial component of the optical system was being explored. This system is designed to create continuous wave laser beams in the deep UV range. The crystal has to be embedded between two prisms. Roughness and shape of the crystal is ensured via the polishing process which alone has many influencing factors and was examined at the beginning of the project. The quality of the crystal can be as good as it can be, but if the contacting prisms do not fit, the whole prism-coupled device will become unusable in the overall optical laser system. The performance of the laser can only be achieved by harmonizing all elements of the PCD and the PCD itself into the laser set-up. In the current phase of the project this question will be dealt with. The prism-coupled device is split up into its individual parts, which are the nonlinear crystal, the prisms as optical auxiliary components, micro screws and mechanical support. Going through the requirements to the properties of the crystal and their limitations, the influence of the PCD on the optical performance of the crystal is presented. Here, the main focus is placed on the mode of fixing the crystal between the prisms and on putting the stack of crystal and prisms in the laser beam. The influencing factors between the crystal, the prisms and the method of fixing the PCD are described.
Contribution
  • Christian Vogt
  • Helge Thiess
  • J. Blasl
  • N. Hanenkamp
  • Klaus Lichtinger

Superposition of cryogenic and ultrasonic assisted machining of Zerodur.

In: Tenth European Seminar on Precision Optics Manufacturing. pg. 15

  • Eds.:
  • Christine Wünsche
  • Alexander Haberl
  • O. Fähnle
  • Gerald Fütterer

SPIE, Society of Photo-Optical Instrumentation Engineers

  • (2023)

DOI: 10.1117/12.2678074

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Cryogenic machining is a cooling strategy that has recently been frequently found in research in machining processes for materials such as inconel or titanium. In particular it is reported that these processes are more efficient in terms of tool life and material removal rate compared to those with water-based cooling lubrication. An increase in efficiency and productivity has significant potential from a cost perspective, especially when grinding Ceramic Matrix Composite materials and similar. These processes are used, for example, in the lightweighting of telescope mirrors made of e.g. fiber-reinforced silicon carbide, or Zerodur. An increase in productivity would be clearly noticeable in the manufacturing costs due to normally long machining times. In the "KryoSonic" project, we investigated whether and to what extent the use of cryogenic machining affects the rough machining of Zerodur with and without ultrasonic support.
Contribution
  • Michael Wagner

Simulation of System Transmission Values for different Angles of Incidence.

In: Tenth European Seminar on Precision Optics Manufacturing. pg. 1275509

  • Eds.:
  • Christine Wünsche
  • Alexander Haberl
  • O. Fähnle
  • Gerald Fütterer

SPIE, Society of Photo-Optical Instrumentation Engineers

  • (2023)

DOI: 10.1117/12.2676121

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For the design of a new asphere measuring system, it is necessary to know transmission values for a system consisting of a source, an optional auxiliary filter and an optical filter, on which angle-tuning is performed. To generate these transmission values for different angles of incidence and polarizations a simulation program was created. Input data of the simulation were based on data provided by the manufacturers. Simulation results are presented for a sample of four systems. Simulation was deemed successful and accelerates the design process of the metrology system, since a large range of source and filter combinations can be evaluated swiftly. Limitations of the simulation are discussed as well.
Contribution
  • Gerald Fütterer

Reticles in autocollimators: change in image quality due to changed coherence properties.

In: Eleventh European Seminar on Precision Optics Manufacturing 2024. pg. 1322103

  • Eds.:
  • Helge Thiess
  • Christine Wünsche
  • Alexander Haberl
  • O. Fähnle
  • Gerald Fütterer

SPIE

DOI: 10.1117/12.3035187

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Autocollimators (AC) are used for different metrological measurement tasks. These instruments are compact and versatile and easy to use. Angle deviations of polygons, local slopes, fiducials, e.g., are measured with autocollimators. If calibrated electronic autocollimators are used, then the measurements can be performed with uncertainties down to 0.01 arc sec. The uncertainty might be increased further by one order of magnitude or more if surfaces with small apertures, aberrant surfaces or surfaces placed at long working distances are measured. To define the measuring window, respectively the limiting parameters, a model of the optical system was implemented. Aberrations, diffraction, temporal and spatial coherence are used. To increase the measurement range, a phase-shifting reticle can be used. Simulations made for small apertures show, that a significant reduction of the uncertainty can only be realized for a limited parameter range of the components used. For example, incoherent and coherent illumination are rather exceptions than standards. Partial coherence is used in a plurality of applications, e.g. for interferometry and space-bandwidth-limited wave front reconstruction, just to name a few. The system and the coherence function Γ must be tailored to provide specific operation. Almost all embodiments come with little changes of the light source's coherence properties only. For example, to use a spectral bandpass filter or to limit the size of the light source seems to be the standard solution for almost everything. Some error sources related to reticle imaging within an AC are identified. And the acceptable parameter range will be described.
Contribution
  • Christian Vogt
  • Ghanshyam Babariya
  • Olga Kukso

An experimental approach to temperature measurement in the contact zone when grinding brittle-hard materials.

In: Eleventh European Seminar on Precision Optics Manufacturing 2024. pg. 132210E

  • Eds.:
  • Helge Thiess
  • Christine Wünsche
  • Alexander Haberl
  • O. Fähnle
  • Gerald Fütterer

SPIE

  • (2024)

DOI: 10.1117/12.3030935

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Temperature is an important process factor in grinding. Cryogenic cooling has proven to be very successful in metal machining, for example, as oxidation is prevented by lowering the temperature level. This enables significantly higher cutting speeds and longer tool life. In our research, we aim to determine whether similar effects occur when grinding brittle-hard materials, which is why the temperature in the contact zone is explicitly examined here. This article presents a very simple and extremely cost-effective approach using a germanium window and an infrared temperature sensor. It explains how the system is constructed, what results can be achieved with it and how the system compares to other commercially available approaches.