Contribution
  • Michael Wagner
  • Gerald Fütterer
Computer-aided beam path generation and assessment for Stevick-Paul telescopes
  • 2020

DOI: 10.1117/12.2564852

At Deggendorf Institute of Technology a student project is currently under way to build a Stevick-Paul telescope for astrophotography. An important step in the overall development procedure of each telescope is the design of a beam-path and ensuring its suitability under optical and engineering aspects. The students performed this process in a sequential manner by using several different computer programs (e.g. MATLAB, Zemax, Creo Parametric). To accelerate the beam path design process, a Python program to automate the major part of the design process with minimum human supervision was created. The input data of the python program consists of ranges of the desired characteristics of the Stevick-Paul telescope, such as focal lengths, primary mirror diameters and tilts etc., mirror thickness and mount geometries, as well as the specific type of camera. After setting the input, the program creates 2D cross-sections of beam paths according to the formulas of D. Stevick and may introduce a flat fold mirror to reduce the overall system size as well as improve the accessibility of the focus plane. The subsequent assessment routine checks against the susceptibility for stray light and performs a complex analysis of the available installation space to ensure sufficient mechanical tolerances. In this way, collisions between mirrors, mounts and cameras are avoided and obstructions of the beam path are prevented. At any stage, the program can produce graphical representations of the beam paths. In this paper the computer-aided design of a telescope beam path with a focal length of 2400 mm is demonstrated. During development of the software, a subset of folded Stevick-Paul telescopes, in which certain components are parallel, was found. This subset may be useful to simplify the alignment procedure. In conclusion, further refinement of the software is necessary, although the program is already a useful aid for certain aspects when creating a beam path design.
Contribution
  • Michael Wagner
  • Gerald Fütterer
Computer-aided beam path generation and assessment for Stevick-Paul telescopes
  • 2020

DOI: 10.1117/12.2564852

At Deggendorf Institute of Technology a student project is currently under way to build a Stevick-Paul telescope for astrophotography. An important step in the overall development procedure of each telescope is the design of a beam-path and ensuring its suitability under optical and engineering aspects. The students performed this process in a sequential manner by using several different computer programs (e.g. MATLAB, Zemax, Creo Parametric). To accelerate the beam path design process, a Python program to automate the major part of the design process with minimum human supervision was created. The input data of the python program consists of ranges of the desired characteristics of the Stevick-Paul telescope, such as focal lengths, primary mirror diameters and tilts etc., mirror thickness and mount geometries, as well as the specific type of camera. After setting the input, the program creates 2D cross-sections of beam paths according to the formulas of D. Stevick and may introduce a flat fold mirror to reduce the overall system size as well as improve the accessibility of the focus plane. The subsequent assessment routine checks against the susceptibility for stray light and performs a complex analysis of the available installation space to ensure sufficient mechanical tolerances. In this way, collisions between mirrors, mounts and cameras are avoided and obstructions of the beam path are prevented. At any stage, the program can produce graphical representations of the beam paths. In this paper the computer-aided design of a telescope beam path with a focal length of 2400 mm is demonstrated. During development of the software, a subset of folded Stevick-Paul telescopes, in which certain components are parallel, was found. This subset may be useful to simplify the alignment procedure. In conclusion, further refinement of the software is necessary, although the program is already a useful aid for certain aspects when creating a beam path design.
Contribution
  • Gerald Fütterer
Wave front sensing for metrology by using optical filter
  • 2019

DOI: 10.1117/12.2530013

An interferometric problem is the limited fringe density, which is due to the limited allowed slope difference of superimposed wave fronts. Thus, the angular dynamic range of measurable surfaces and objects under test is limited. In other words, all shapes that deviate from a plane surface or a sphere represent a measuring problem in interferometers, or require an individually adapted null optics, which might cost e.g. 10 k∈ or more. In addition, ground surfaces cannot be measured in standard interferometers, except by using Speckle interferometry, which is limited in resolution. Freeform optics are very problematic. Even when polished, only tactile or confocal coordinate measurement might work. Several interferometers address the problem of the angular deviation to a sphere. For instance, lateral stitching on a curved surface, which is equivalent to the best-fit sphere, or longitudinal stitching is used. To use a tilted wave interferometer for asphere metrology is another option, which provides versatile measurement configurations. The approach discussed here is to use optical filters. The development of this technique is part of a project most recently started at the Technology Campus in Teisnach. The surface under test (SUT) is imaged onto an optical filter, which has a calibrated angular selectivity. Thus, the angles of the local wave front normal vectors are transferred into an intensity distribution. A set of angular measurements enables reduced uncertainty of the wave front measurement. Aspects as e.g. the working principle, boundary conditions and the identification of practical filters are discussed in the paper.
Contribution
  • Gerald Fütterer
  • Michael Wagner
  • Lucas Bauer
  • Simon Wittl
4-Schiefspiegel-Teleskop: Justage und Stabilitätsaspekte
  • 2019
Contribution
  • Gerald Fütterer
  • Michael Wagner
  • Lucas Bauer
  • Simon Wittl
Four-Tilted-Mirror Telescope: Alignment and Stability Aspects
  • 2019
Patent
  • Gerald Fütterer
  • N. Leister
  • R. Haussler
  • G. Lazarev
Spatial light modulator device for the modulation of a wave field with compex information
  • 2019
Lecture
  • Gerald Fütterer
4x-Schiefspiegel-Teleskop-Projekt Posterpräsentation
  • 2019
Patent
  • Gerald Fütterer
Beam divergence and various collimators for holographic or stereoscopic displays
  • 2019
Patent
  • Gerald Fütterer
Beam divergence and various collimators for holographic or stereoscopic displays
  • 2019
Lecture
  • Gerald Fütterer
Wave front sensing for metrology by using optical filter
  • 2019
Lecture
Contribution
  • Gerald Fütterer
  • Michael Wagner
  • Lucas Bauer
  • Simon Wittl
4-Schiefspiegel-Teleskop: Justage und Stabilitätsaspekte
  • 2019
Contribution
  • Gerald Fütterer
  • Michael Wagner
  • Lucas Bauer
  • Simon Wittl
Alignment and thermal drift aspects of a four-tilted-mirror student project telescope
  • 2019

DOI: 10.1117/12.2530076

The Deggendorf Institute of Technology (DIT) and its Faculty of Applied Natural Sciences and Industrial engineering transfer a broad spectrum of knowledge to the students. The clarification of the interrelations that exist between seemingly isolated fields of knowledge is a permanent process. In order to put this into practice, a telescope construction project was started. The base of the in-house student project is the Technology Campus in Teisnach, which bundles capacities for process development, production and measurement of high-precision optics, including telescope optics. A first optical design, which is based on a subset of the parameter space published in 1989 by M. Brunn1, 2 (later built by D. Stevick as f/12-system3 ), made use of a primary mirror M1 with a diameter of 400 mm. An f/8-system provide a Strehl ratio SR ≥ 0.8 over an entire field of view of 0.7° deg. Even if this seems to be sufficient, manufacturing tolerances, adjustment tolerances, thermal drift and positional changes considerably reduce the Strehl ratio. In order to obtain reliable values of acceptable tolerances, statistical Monte Carlo analyses had been carried out. As consequences, the tube design was changed and the design of new mirror mounts started. This was done to achieve the required stiffness. The new tube designs, one based on carbon-fiber-reinforced polymer (CFRP) and one based on FeNi36, had been tested by using FEM analysis. In addition, the practicability of deep learning based aberration detection was tested. Zernike polynomials obtained by analyzing the star images with a Convolutional Neuronal Network (CNN). The current state of the development is described.
Lecture
  • Gerald Fütterer
4x-Schiefspiegel-Teleskop-Projekt Posterpräsentation
  • 2019
Patent
  • Gerald Fütterer
  • N. Leister
  • R. Haussler
  • G. Lazarev
Spatial light modulator device for the modulation of a wave field with compex information
  • 2019
Lecture
Contribution
  • Gerald Fütterer
Wave front sensing for metrology by using optical filter
  • 2019

DOI: 10.1117/12.2530013

An interferometric problem is the limited fringe density, which is due to the limited allowed slope difference of superimposed wave fronts. Thus, the angular dynamic range of measurable surfaces and objects under test is limited. In other words, all shapes that deviate from a plane surface or a sphere represent a measuring problem in interferometers, or require an individually adapted null optics, which might cost e.g. 10 k∈ or more. In addition, ground surfaces cannot be measured in standard interferometers, except by using Speckle interferometry, which is limited in resolution. Freeform optics are very problematic. Even when polished, only tactile or confocal coordinate measurement might work. Several interferometers address the problem of the angular deviation to a sphere. For instance, lateral stitching on a curved surface, which is equivalent to the best-fit sphere, or longitudinal stitching is used. To use a tilted wave interferometer for asphere metrology is another option, which provides versatile measurement configurations. The approach discussed here is to use optical filters. The development of this technique is part of a project most recently started at the Technology Campus in Teisnach. The surface under test (SUT) is imaged onto an optical filter, which has a calibrated angular selectivity. Thus, the angles of the local wave front normal vectors are transferred into an intensity distribution. A set of angular measurements enables reduced uncertainty of the wave front measurement. Aspects as e.g. the working principle, boundary conditions and the identification of practical filters are discussed in the paper.
Contribution
  • Gerald Fütterer
  • Michael Wagner
  • Lucas Bauer
  • Simon Wittl
Alignment and thermal drift aspects of a four-tilted-mirror student project telescope
  • 2019

DOI: 10.1117/12.2530076

The Deggendorf Institute of Technology (DIT) and its Faculty of Applied Natural Sciences and Industrial engineering transfer a broad spectrum of knowledge to the students. The clarification of the interrelations that exist between seemingly isolated fields of knowledge is a permanent process. In order to put this into practice, a telescope construction project was started. The base of the in-house student project is the Technology Campus in Teisnach, which bundles capacities for process development, production and measurement of high-precision optics, including telescope optics. A first optical design, which is based on a subset of the parameter space published in 1989 by M. Brunn1, 2 (later built by D. Stevick as f/12-system3 ), made use of a primary mirror M1 with a diameter of 400 mm. An f/8-system provide a Strehl ratio SR ≥ 0.8 over an entire field of view of 0.7° deg. Even if this seems to be sufficient, manufacturing tolerances, adjustment tolerances, thermal drift and positional changes considerably reduce the Strehl ratio. In order to obtain reliable values of acceptable tolerances, statistical Monte Carlo analyses had been carried out. As consequences, the tube design was changed and the design of new mirror mounts started. This was done to achieve the required stiffness. The new tube designs, one based on carbon-fiber-reinforced polymer (CFRP) and one based on FeNi36, had been tested by using FEM analysis. In addition, the practicability of deep learning based aberration detection was tested. Zernike polynomials obtained by analyzing the star images with a Convolutional Neuronal Network (CNN). The current state of the development is described.
Lecture
  • Gerald Fütterer
Wave front sensing for metrology by using optical filter
  • 2019
Contribution
  • Gerald Fütterer
  • Michael Wagner
  • Lucas Bauer
  • Simon Wittl
Four-Tilted-Mirror Telescope: Alignment and Stability Aspects
  • 2019
Lecture
  • Gerald Fütterer
CSLM illumination for 1D and 2D encoded holographic 3D displays
  • 2018
Contribution
  • Gerald Fütterer
  • A. Sperl
  • A. Engelbrecht
  • Simon Killinger
  • M. Werni
  • W. Krais
Abschattungsfreies Multi-Schiefspiegel-Teleskop als studentisches Entwicklungsprojekt
  • 2018
An der Fakultät für Angewandte Naturwissenschaften und Wirtschaftsingenieurwesen der Technische Hochschule Deggendorf wird ein breites Wissensspektrum vermittelt. Um dieses praxisnah zu gestalten, wurde ein Teleskopbau-Projekt ins Leben gerufen. Mit dem Technologie-Campus Teisnach existiert die Basis für die Fertigung und Messung hoch präziser Teleskop-Optiken. Ausgangsparameter sind 400 mm Durchmesser des Primärspiegels und der Ansatz, am Markt bestehende Systeme in der optischen Abbildungsleistung einzuholen. Das optische Design beruht auf einer Untermenge des Parameterraums, der 1989 von M. Brunn veröffentlicht wurde. Das Konzept wurde später von D. Stevick als F12 System (mit Bezug auf die Arbeit von M. Paul, 1935) gebaut. Das THD-Projekt startete mit einem Vergleich von F7 Systemen, die in Zemax implementiert wurden. Die Abbildungsleistung wurde über ein Feld von 0,7 ° deg verglichen. Das mechanische Design schließt FEM Simulation thermischer Effekte an leichtgewichteten Spiegeln ein. Unterschiedliche Tuben wurden miteinander verglichen, einschließlich CFK Monocoquetubus. Ein weiterer Punkt ist die Auslegung der Nachführung. Es wird der Stand der Entwicklung dargelegt.
Contribution
  • Gerald Fütterer
Optimization of the complex coherence function for diffraction-based wavefront transformations
  • 2018

DOI: 10.1117/12.2307245

Partial coherence is used in a plurality of applications, magnifying microscopic imaging, interferometric measurement, lithographic imaging, CGH based wave front shaping, interference lithography and space-bandwidth-limited wave front reconstruction, just to name a few. In some applications the primary light source is characterized by a limited coherence length and an extended angular spectrum of plane waves, which has to be narrowed, e.g. if an Excimer laser is used. Sometimes the angular spectrum of plane waves of the primary light source has to be increased in order to be practical. There are several possibilities in general, the primary light source can be used directly, the system has to be adapted or the coherence function Γ has to be tailored in order to provide the specific requirements. Almost all embodiments come with little changes of the light sources coherence properties only. For example, to use a spectral bandpass filter or to limit the size of the light source seem to be the standard solution for almost everything. However, more advanced tailoring of the complex valued coherence function Γ leads to an increased image quality, e.g. in interferometers, but is not limited to this, reduces background noise, decouples Fizeau cavities or it enables complete new illumination and imaging system designs, which provide unique features. This aspect will be discussed herein. Furthermore, the propagation of the complex coherence will be taken into account. This is done in order to provide defined conditions in defined planes of imaging devices. In other words, the usage of the Wiener-Khintchin theorem and the van Cittert-Zernike theorem is just a part of the system analysis and system optimization, which has to be done. Although generic approaches are used, discrete light source layouts are strongly related to the discrete optical devices, which make use of them. The specific tailoring of the complex coherence function, which is related to the space-bandwidth-limited reconstruction of wave front segments, which also can be referred to as space-bandwidth-limited CGH reconstruction, will be described in more detail. For this type of real time dynamic imaging two major problems - among several others - have to be solved. One problem is the huge computation power and the other one is the coherent retinal cross talk of adjacent image points, which are reconstructed in the image volume. The disclosed layouts of tailored secondary light sources are based on the Wiener-Khintchin theorem and the van Cittert-Zernike theorem. Both problems, which are mentioned above, can be solved. Tailored complex valued light sources reduce the required computation power by enabling reduced coherent overlay of sub-CGH areas. Furthermore, they reduce the coherent retinal cross talk of dynamic real time spacebandwidth- limited CGH reconstruction, which is used in advanced imaging applications, too. This results in an increased image quality of partial coherent wave field reconstruction based imaging.
Lecture
  • Gerald Fütterer
  • A. Sperl
  • Simon Killinger
  • A. Engelbrecht
  • M. Werni
  • W. Krais
Developing a four-tilted-mirror telescope as a student project
  • 2018
Lecture
  • Alexander Haberl
  • H. Harsch
  • Gerald Fütterer
  • Johannes Liebl
  • C. Pruß
  • Rolf Rascher
  • W. Osten
Model based error separation of power spectral density artefacts in wavefront measurement
  • 2018
Contribution
  • Gerald Fütterer
  • A. Sperl
  • A. Engelbrecht
  • Simon Killinger
  • M. Werni
  • W. Krais
Abschattungsfreies Multi-Schiefspiegel-Teleskop als studentisches Entwicklungsprojekt
  • 2018
An der Fakultät für Angewandte Naturwissenschaften und Wirtschaftsingenieurwesen der Technische Hochschule Deggendorf wird ein breites Wissensspektrum vermittelt. Um dieses praxisnah zu gestalten, wurde ein Teleskopbau-Projekt ins Leben gerufen. Mit dem Technologie-Campus Teisnach existiert die Basis für die Fertigung und Messung hoch präziser Teleskop-Optiken. Ausgangsparameter sind 400 mm Durchmesser des Primärspiegels und der Ansatz, am Markt bestehende Systeme in der optischen Abbildungsleistung einzuholen. Das optische Design beruht auf einer Untermenge des Parameterraums, der 1989 von M. Brunn veröffentlicht wurde. Das Konzept wurde später von D. Stevick als F12 System (mit Bezug auf die Arbeit von M. Paul, 1935) gebaut. Das THD-Projekt startete mit einem Vergleich von F7 Systemen, die in Zemax implementiert wurden. Die Abbildungsleistung wurde über ein Feld von 0,7 ° deg verglichen. Das mechanische Design schließt FEM Simulation thermischer Effekte an leichtgewichteten Spiegeln ein. Unterschiedliche Tuben wurden miteinander verglichen, einschließlich CFK Monocoquetubus. Ein weiterer Punkt ist die Auslegung der Nachführung. Es wird der Stand der Entwicklung dargelegt.
Patent
  • Gerald Fütterer
Display Device, holographic head-mounted display
  • 2018
Lecture
  • Gerald Fütterer
  • A. Sperl
  • A. Engelbrecht
  • Simon Killinger
  • M. Werni
  • W. Krais
Abschattungsfreies Multi-Schiefspiegel-Teleskop als studentisches Entwicklungsprojekt
  • 2018
Lecture
  • Gerald Fütterer
CSLM illumination for 1D and 2D encoded holographic 3D displays
  • 2018
Contribution
  • Alexander Haberl
  • H. Harsch
  • Gerald Fütterer
  • Johannes Liebl
  • C. Pruß
  • Rolf Rascher
  • W. Osten
Model based error separation of power spectral density artefacts in wavefront measurement
  • 2018

DOI: 10.1117/12.2321106

Contribution
  • Gerald Fütterer
  • Johannes Liebl
  • Alexander Haberl
Contribution of the phase transfer function of extended measurement cavities to mid spatial frequencies and the overall error budget
  • 2018

DOI: 10.1117/12.2318711

A challenge of coaxial - measurement cavity based - interferometer is to realize an interference contrast in the vicinity of one and to realize a complete elimination of the parasitic reflections. Another challenge, which also exists in non-coaxial setups, is the phase transfer function of extended measurement cavities. Ideally, the surface under test (SUT) and the reference surface (REF) are both exactly imaged onto the detector plane. In practice, SUT and REF have to be placed within the depth of field (DOF), which refers to the object space. The term depth of focus refers to the image space. To avoid confusion, the depth of field might be referred to as DOOF (depth of object field) and the depth of focus might be referred to as DOIF (depth of image field). However, in many measurement situations, the REF is not placed within the DOOF, which is the small z-range, which is imaged onto the detector plane. Furthermore, the phase transfer function (PTF) of the REF and the image distortion of the REF are both dependent on the focal plane used to image the SUT onto the detector plane. Effects as phase deformation, image distortion and image blurring have to be taken into account when using extended measurement cavities. This can be done by using a look up table (LUT), which contains simulated and/or calibrated data. Thus, the related system error can be subtracted. A remaining challenge is an unknown object under test (OUT), which is measured by using a double path arrangement. The measured wave front depends on the two surfaces of the OUT and the position of the return mirror. For simplicity, a homogeneous substrate and a perfect return mirror might be presumed. The simulation of waves propagating within extended measurement cavities, as well as measurement results, will be discussed. In addition, the influence on the power spectral density (PSD) will be described. This is important for high end correction techniques as e.g. magneto rheological figuring (MRF) and ion beam figuring (IBF).
Lecture
  • Gerald Fütterer
Optimization of the complex coherence function for diffraction-based wavefront transformations
  • 2018
Lecture
  • Gerald Fütterer
  • A. Sperl
  • Simon Killinger
  • A. Engelbrecht
  • M. Werni
  • W. Krais
Developing a four-tilted-mirror telescope as a student project
  • 2018
Lecture
  • Gerald Fütterer
Etalon effect suppression in optical measurements by using complex coherence optimization Posterpräsentation
  • 2018
Contribution
  • Gerald Fütterer
CSLM illumination for 1D and 2D encoded holographic 3D displays
  • 2018

DOI: 10.1117/12.2312745

To leave the path of classic holography and limit the space-bandwidth-product of the holographic reconstruction is one way to enable interactive real time holographic 3D displays. Thus, a couple of major problems - among several others - can be reduced to a practical level. This holds e.g. for the computation power, the data transfer rate and the pixel count of the spatial light modulator (SLM) used. Although this idea is almost twenty years old, the maximum time span of IP protection, displays based on space-bandwidth-limited CGH reconstruction, which also can be referred to as spacebandwidth- limited reconstruction of wave front segments, are still not on the market. There are several technological reasons for that. However, the technological barriers can be tackled gradually. One problem to be solved is the illumination of the entrance plane of the preferable complex valued spatial light modulator (CSLM). Here, CSLM means to modulate the phase and the amplitude of each pixel. The display diagonals of desktop and TV type CSLM might be e.g. 32 and 65 inch respectively. In other words, reasonable large collimated illumination wave fields are mandatory. In addition a small form factor is a must have in order to obtain commercial success. The solution is an optical system design, which is based on Bragg diffraction based volume gratings. Classic refractive optics fails here. In other words, Bragg diffraction based volume gratings are key components of illumination units of holographic 3D displays. They can be used within a parameter space, which cannot be addressed by surface relief type diffraction optics. But their layout depends on the parameters of the illumination wave field, which has to be tailored in regards to the optical system of the discrete, e.g. 1D or 2D encoded holographic 3D display. This will be described in more detail. The example used for the description is a double wedge type backlight unit. Furthermore, it will be explained why the use of complex valued secondary light sources is a must have in holographic 3D displays. For this, a short explanation of coherent retinal inter object point cross talk will be given too. Finally, the description of the wave field shaping (WFS), which is required in order to form the optimized complex valued light source planes, is provided. In other words, a description of a tailored coherence preparation is given, which is up to now not state of the art. The cause and effect relationship of the light propagating from the primary light sources, which are lasers, to the final receptor, which is the retina, will be pointed out. Although this tailored partial coherent illumination totally differs from the state of the art of information displays, it might help to understand a technology, which will come in the next decades.
Contribution
  • Gerald Fütterer
Optimization of the complex coherence function for diffraction-based wavefront transformations
  • 2018

DOI: 10.1117/12.2307245

Partial coherence is used in a plurality of applications, magnifying microscopic imaging, interferometric measurement, lithographic imaging, CGH based wave front shaping, interference lithography and space-bandwidth-limited wave front reconstruction, just to name a few. In some applications the primary light source is characterized by a limited coherence length and an extended angular spectrum of plane waves, which has to be narrowed, e.g. if an Excimer laser is used. Sometimes the angular spectrum of plane waves of the primary light source has to be increased in order to be practical. There are several possibilities in general, the primary light source can be used directly, the system has to be adapted or the coherence function Γ has to be tailored in order to provide the specific requirements. Almost all embodiments come with little changes of the light sources coherence properties only. For example, to use a spectral bandpass filter or to limit the size of the light source seem to be the standard solution for almost everything. However, more advanced tailoring of the complex valued coherence function Γ leads to an increased image quality, e.g. in interferometers, but is not limited to this, reduces background noise, decouples Fizeau cavities or it enables complete new illumination and imaging system designs, which provide unique features. This aspect will be discussed herein. Furthermore, the propagation of the complex coherence will be taken into account. This is done in order to provide defined conditions in defined planes of imaging devices. In other words, the usage of the Wiener-Khintchin theorem and the van Cittert-Zernike theorem is just a part of the system analysis and system optimization, which has to be done. Although generic approaches are used, discrete light source layouts are strongly related to the discrete optical devices, which make use of them. The specific tailoring of the complex coherence function, which is related to the space-bandwidth-limited reconstruction of wave front segments, which also can be referred to as space-bandwidth-limited CGH reconstruction, will be described in more detail. For this type of real time dynamic imaging two major problems - among several others - have to be solved. One problem is the huge computation power and the other one is the coherent retinal cross talk of adjacent image points, which are reconstructed in the image volume. The disclosed layouts of tailored secondary light sources are based on the Wiener-Khintchin theorem and the van Cittert-Zernike theorem. Both problems, which are mentioned above, can be solved. Tailored complex valued light sources reduce the required computation power by enabling reduced coherent overlay of sub-CGH areas. Furthermore, they reduce the coherent retinal cross talk of dynamic real time spacebandwidth- limited CGH reconstruction, which is used in advanced imaging applications, too. This results in an increased image quality of partial coherent wave field reconstruction based imaging.
Contribution
  • Gerald Fütterer
  • A. Sperl
  • Simon Killinger
  • A. Engelbrecht
  • M. Werni
  • W. Krais
Developing a four-tilted-mirror telescope as a student project
  • 2018

DOI: 10.1117/12.2320542

The Faculty of Applied Natural Sciences and Industrial engineering, which is a part of the Deggendorf Institute of Technology (DIT), transfers a broad spectrum of knowledge to the students. Edifying the interrelations, which are present between seemingly isolated fields of knowledge, is a permanent process. In order to make this practical, a telescope construction project was launched. The Technology Campus Teisnach bundles capacities for process development, production and measurement of highprecision optics. This also includes telescope optics. This qualifies the Campus for being the base of the in-house project. Fixed boundary conditions are e.g. 400 mm diameter of the primary mirror M1 and the objective to realize an image performance, which is equivalent to commercial telescopes. Furthermore, an unobscured tilted-mirror-system should be realized. The optical design, which was chosen as a result of an analysis of the state of the art, is based on a subset of the parameter space, which was published in 1989 by M. Brunn 1, 2. The concept was later built by D. Stevick as f/12-system (with reference to the work of M. Paul, 1935) 3. The DIT project started with a comparison of f/7-systems. They had been implemented in the optical design software Zemax. The imaging performance was compared within a field of view of 0.7 ° deg. The mechanical design includes FEM simulation of thermal effects on slightly weighted mirrors. Different tubes had been compared, including carbonfiber- reinforced-polymer (CFRP) Monocoquetubus. Another task is the realization of fast and precise tracking. The state of the development is set out.
Lecture
  • Gerald Fütterer
  • A. Sperl
  • A. Engelbrecht
  • Simon Killinger
  • M. Werni
  • W. Krais
Abschattungsfreies Multi-Schiefspiegel-Teleskop als studentisches Entwicklungsprojekt
  • 2018
Contribution
  • Gerald Fütterer
  • A. Sperl
  • Simon Killinger
  • A. Engelbrecht
  • M. Werni
  • W. Krais
Developing a four-tilted-mirror telescope as a student project
  • 2018

DOI: 10.1117/12.2320542

The Faculty of Applied Natural Sciences and Industrial engineering, which is a part of the Deggendorf Institute of Technology (DIT), transfers a broad spectrum of knowledge to the students. Edifying the interrelations, which are present between seemingly isolated fields of knowledge, is a permanent process. In order to make this practical, a telescope construction project was launched. The Technology Campus Teisnach bundles capacities for process development, production and measurement of highprecision optics. This also includes telescope optics. This qualifies the Campus for being the base of the in-house project. Fixed boundary conditions are e.g. 400 mm diameter of the primary mirror M1 and the objective to realize an image performance, which is equivalent to commercial telescopes. Furthermore, an unobscured tilted-mirror-system should be realized. The optical design, which was chosen as a result of an analysis of the state of the art, is based on a subset of the parameter space, which was published in 1989 by M. Brunn 1, 2. The concept was later built by D. Stevick as f/12-system (with reference to the work of M. Paul, 1935) 3. The DIT project started with a comparison of f/7-systems. They had been implemented in the optical design software Zemax. The imaging performance was compared within a field of view of 0.7 ° deg. The mechanical design includes FEM simulation of thermal effects on slightly weighted mirrors. Different tubes had been compared, including carbonfiber- reinforced-polymer (CFRP) Monocoquetubus. Another task is the realization of fast and precise tracking. The state of the development is set out.
Contribution
  • Gerald Fütterer
CSLM illumination for 1D and 2D encoded holographic 3D displays
  • 2018

DOI: 10.1117/12.2312745

To leave the path of classic holography and limit the space-bandwidth-product of the holographic reconstruction is one way to enable interactive real time holographic 3D displays. Thus, a couple of major problems - among several others - can be reduced to a practical level. This holds e.g. for the computation power, the data transfer rate and the pixel count of the spatial light modulator (SLM) used. Although this idea is almost twenty years old, the maximum time span of IP protection, displays based on space-bandwidth-limited CGH reconstruction, which also can be referred to as spacebandwidth- limited reconstruction of wave front segments, are still not on the market. There are several technological reasons for that. However, the technological barriers can be tackled gradually. One problem to be solved is the illumination of the entrance plane of the preferable complex valued spatial light modulator (CSLM). Here, CSLM means to modulate the phase and the amplitude of each pixel. The display diagonals of desktop and TV type CSLM might be e.g. 32 and 65 inch respectively. In other words, reasonable large collimated illumination wave fields are mandatory. In addition a small form factor is a must have in order to obtain commercial success. The solution is an optical system design, which is based on Bragg diffraction based volume gratings. Classic refractive optics fails here. In other words, Bragg diffraction based volume gratings are key components of illumination units of holographic 3D displays. They can be used within a parameter space, which cannot be addressed by surface relief type diffraction optics. But their layout depends on the parameters of the illumination wave field, which has to be tailored in regards to the optical system of the discrete, e.g. 1D or 2D encoded holographic 3D display. This will be described in more detail. The example used for the description is a double wedge type backlight unit. Furthermore, it will be explained why the use of complex valued secondary light sources is a must have in holographic 3D displays. For this, a short explanation of coherent retinal inter object point cross talk will be given too. Finally, the description of the wave field shaping (WFS), which is required in order to form the optimized complex valued light source planes, is provided. In other words, a description of a tailored coherence preparation is given, which is up to now not state of the art. The cause and effect relationship of the light propagating from the primary light sources, which are lasers, to the final receptor, which is the retina, will be pointed out. Although this tailored partial coherent illumination totally differs from the state of the art of information displays, it might help to understand a technology, which will come in the next decades.
Lecture
  • Gerald Fütterer
Optimization of the complex coherence function for diffraction-based wavefront transformations
  • 2018
Lecture
  • Gerald Fütterer
Etalon effect suppression in optical measurements by using complex coherence optimization Posterpräsentation
  • 2018
Contribution
  • Alexander Haberl
  • H. Harsch
  • Gerald Fütterer
  • Johannes Liebl
  • C. Pruß
  • Rolf Rascher
  • W. Osten
Model based error separation of power spectral density artefacts in wavefront measurement
  • 2018

DOI: 10.1117/12.2321106

Contribution
  • Gerald Fütterer
  • Johannes Liebl
  • Alexander Haberl
Contribution of the phase transfer function of extended measurement cavities to mid spatial frequencies and the overall error budget
  • 2018

DOI: 10.1117/12.2318711

A challenge of coaxial - measurement cavity based - interferometer is to realize an interference contrast in the vicinity of one and to realize a complete elimination of the parasitic reflections. Another challenge, which also exists in non-coaxial setups, is the phase transfer function of extended measurement cavities. Ideally, the surface under test (SUT) and the reference surface (REF) are both exactly imaged onto the detector plane. In practice, SUT and REF have to be placed within the depth of field (DOF), which refers to the object space. The term depth of focus refers to the image space. To avoid confusion, the depth of field might be referred to as DOOF (depth of object field) and the depth of focus might be referred to as DOIF (depth of image field). However, in many measurement situations, the REF is not placed within the DOOF, which is the small z-range, which is imaged onto the detector plane. Furthermore, the phase transfer function (PTF) of the REF and the image distortion of the REF are both dependent on the focal plane used to image the SUT onto the detector plane. Effects as phase deformation, image distortion and image blurring have to be taken into account when using extended measurement cavities. This can be done by using a look up table (LUT), which contains simulated and/or calibrated data. Thus, the related system error can be subtracted. A remaining challenge is an unknown object under test (OUT), which is measured by using a double path arrangement. The measured wave front depends on the two surfaces of the OUT and the position of the return mirror. For simplicity, a homogeneous substrate and a perfect return mirror might be presumed. The simulation of waves propagating within extended measurement cavities, as well as measurement results, will be discussed. In addition, the influence on the power spectral density (PSD) will be described. This is important for high end correction techniques as e.g. magneto rheological figuring (MRF) and ion beam figuring (IBF).
Lecture
  • Alexander Haberl
  • H. Harsch
  • Gerald Fütterer
  • Johannes Liebl
  • C. Pruß
  • Rolf Rascher
  • W. Osten
Model based error separation of power spectral density artefacts in wavefront measurement
  • 2018
Patent
  • Gerald Fütterer
Display Device, holographic head-mounted display
  • 2018
Contribution
  • Gerald Fütterer
Tailored complex degree of mutual coherence for plane-of-interest interferometry with reduced measurement uncertainty
  • 2017

DOI: 10.1117/12.2279834

A problem of interferometers is the elimination of parasitic reflections. Parasitic reflections and modulated intensity signals, which are not related to the reference surface (REF) or the surface under test (SUT) in a direct way, can increase the measurement uncertainty significantly. In some situations standard methods might be used in order to eliminate reflections from the backside of the optical element under test. For instance, match the test object to an absorber, while taking the complex refractive index into account, can cancel out back reflections completely. This causes additional setup time and chemical contamination. In some situations an angular offset might be combined with an aperture stop. This reduces spatial resolution and it does not work if the disturbing wave field propagates in the same direction as the wave field, which propagates from the SUT. However, a stack of surfaces is a problem. An increased spectral bandwidth might be used in order to obtain a separation of the plane-of-interest from other planes. Depending on the interferometer used, this might require an optical path difference of zero or it might cause a reduction of the visibility to V < 0.5. Contrary to these methods, a tailored complex degree of mutual coherence can be used. High visibility is obtained for a single plane-of-interest. Wave fields of interest are shifted against each other. The reduction of the measurement uncertainty, as well as the embodiment of a modified interferometer, will be discussed.
Contribution
  • Gerald Fütterer
Tailored complex degree of mutual coherence for plane-of-interest interferometry with reduced measurement uncertainty
  • 2017

DOI: 10.1117/12.2279834

A problem of interferometers is the elimination of parasitic reflections. Parasitic reflections and modulated intensity signals, which are not related to the reference surface (REF) or the surface under test (SUT) in a direct way, can increase the measurement uncertainty significantly. In some situations standard methods might be used in order to eliminate reflections from the backside of the optical element under test. For instance, match the test object to an absorber, while taking the complex refractive index into account, can cancel out back reflections completely. This causes additional setup time and chemical contamination. In some situations an angular offset might be combined with an aperture stop. This reduces spatial resolution and it does not work if the disturbing wave field propagates in the same direction as the wave field, which propagates from the SUT. However, a stack of surfaces is a problem. An increased spectral bandwidth might be used in order to obtain a separation of the plane-of-interest from other planes. Depending on the interferometer used, this might require an optical path difference of zero or it might cause a reduction of the visibility to V < 0.5. Contrary to these methods, a tailored complex degree of mutual coherence can be used. High visibility is obtained for a single plane-of-interest. Wave fields of interest are shifted against each other. The reduction of the measurement uncertainty, as well as the embodiment of a modified interferometer, will be discussed.
Contribution
  • Gerald Fütterer
Polarization-Fizeau interferometer enabling phase measurement with reduced uncertainty
  • 2017

DOI: 10.1117/12.2272001

Contribution
  • Gerald Fütterer
Polarization-Fizeau interferometer enabling phase measurement with reduced uncertainty
  • 2017

DOI: 10.1117/12.2272001

Patent
Lecture
  • Gerald Fütterer
Advantages of on-axis PBS based Fizeau interferometers
  • 2017
Lecture
  • Gerald Fütterer
Optical surface measurement technologies Invited Talk
  • 2017
Contribution
  • Gerald Fütterer
Fast Fizeau interferometer with polarization selective reference and reduced measurement uncertainty for production integrated measurement
  • 2017
Lecture
  • Gerald Fütterer
Tailored complex degree of mutual coherence for plane-of-interest interferometry with reduced measurement uncertainty
  • 2017
Patent
  • Gerald Fütterer
  • R. Häußler
  • N. Leister
Method for producing holograms
  • 2017
Lecture
  • Gerald Fütterer
  • Johannes Liebl
  • Alexander Haberl
Contribution of the phase transfer function of extended measurement cavities to mid spatial frequencies and the overall error budget
  • 2017
Lecture
  • Gerald Fütterer
  • Johannes Liebl
  • Alexander Haberl
Contribution of the phase transfer function of extended measurement cavities to mid spatial frequencies and the overall error budget
  • 2017
Contribution
  • Gerald Fütterer
Advantages of on-axis PBS based Fizeau interferometers
  • 2017
Patent
  • Gerald Fütterer
A Display for Two-Dimensional and/or Three-Dimensional Images
  • 2017
Lecture
  • Gerald Fütterer
Polarization-Fizeau interferometer enabling phase measurement with reduced uncertainty
  • 2017
Patent
  • Gerald Fütterer
  • R. Häußler
  • B. Kroll
  • N. Leister
  • S. Reichelt
Combined light modulation device for tracking users
  • 2017
Lecture
  • Gerald Fütterer
Optical surface measurement technologies Invited Talk
  • 2017
Patent
  • Gerald Fütterer
A Display for Two-Dimensional and/or Three-Dimensional Images
  • 2017
Lecture
  • Gerald Fütterer
Polarization-Fizeau interferometer enabling phase measurement with reduced uncertainty
  • 2017
Contribution
  • Gerald Fütterer
Fast Fizeau interferometer with polarization selective reference and reduced measurement uncertainty for production integrated measurement
  • 2017
Patent
Lecture
  • Gerald Fütterer
Advantages of on-axis PBS based Fizeau interferometers
  • 2017
Patent
  • Gerald Fütterer
  • R. Häußler
  • N. Leister
Method for producing holograms
  • 2017
Lecture
  • Gerald Fütterer
Tailored complex degree of mutual coherence for plane-of-interest interferometry with reduced measurement uncertainty
  • 2017
Patent
  • Gerald Fütterer
  • R. Häußler
  • B. Kroll
  • N. Leister
  • S. Reichelt
Combined light modulation device for tracking users
  • 2017
Contribution
  • Gerald Fütterer
Advantages of on-axis PBS based Fizeau interferometers
  • 2017
Contribution
  • Gerald Fütterer
Field lens multiplexing in holographic 3D displays by using Bragg diffraction based volume gratings
  • 2016
Patent
  • Gerald Fütterer
  • R. Haussler
  • B. Kroll
  • N. Leister
  • S. Reichelt
Combined Light Modulation Device for Tracking Users
  • 2016
Patent
  • Gerald Fütterer
Display Device, in Particular a Head-Mounted Display, Based on Temporal and Spatial Multiplexing of Hologram Tiles
  • 2016
Patent
  • Gerald Fütterer
Display Device, in Particular a Head-Mounted Display, Based on Temporal and Spatial Multiplexing of Hologram Tiles
  • 2016
Patent
  • Gerald Fütterer
Beam Divergence and Various Collimators for Holgraphic or Stereoscopic Displays
  • 2016
Contribution
  • Gerald Fütterer
From Holographic displays to Volume Gratings and Off-Axis Parabolic Mirrors
  • 2016

DOI: 10.1117/12.2245183

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.
JournalArticle
  • Gerald Fütterer
Enabling Holographic 3D Displays with Bragg Diffraction Based Volume Gratings and First Approaches to the Reduction of Diffractive Cross Talk
  • 2016

DOI: 10.25929/276j-2q41

Photonics products often require enhanced optical functionality, which cannot be provided by state of the art optics. This is the case when high-end optical systems as for example holographic 3D displays are developed. Implementation of Bragg diffraction based volume gratings enables small form factor and high definition (HD) natural viewing experience of 3D objects. This is important for modeling 3D data, prototyping, CAD-CAM, computer-integrated manufacturing (CIM), global 3D teleconferencing and mobile infotainment. For example, holographic 3D displays, which are based on space bandwidth limited wave segment reconstruction, profit from the specific characteristics of thick hologram gratings, which can be referred to as Bragg diffraction based volume gratings. It is explained how to adapt angular, spectral and polarization selectivity in order to provide specific optical functionality, which is mandatory in order to realize HD holographic 3D displays. A short introduction to backlight units (BLU), complex valued spatial light modulators (C-SLM) and combined field lenses (cFL) of holographic 3D displays is given. The description of Bragg diffraction based volume gratings is based on the coupled wave theory (CWT). The usage of the 2nd on-Bragg maximum modulation is described. The advantage of the 2nd Bragg diffraction order is explained. Polarization beam splitter (PBS) geometries are described. Specific layouts of holographic 3D displays are explained. BLU and cFL are evaluated. It is shown how the suppression of diffractive crosstalk can be obtained. Oftmals benötigen neue Produkte der Photonik eine erweiterte optische Funktionalität, die nicht von optischen Standard-Komponenten bereitgestellt werden kann. Dies ist auch für die Entwicklung von holographischen 3D-Displays der Fall. Hierbei ermöglicht die Implementierung von Volumengittern, die auf der Bragg-Beugung basieren, eine kompakte Bauweise und eine natürliche Wahrnehmung von 3D-Objekten in HD-Auflösung. Dies ist für die Modellierung von 3D-Daten, die Erstellung von Prototypen, CAD-CAM, Computer integrierte Fertigung (CIM), weltweit arbeitende Telekonferenz-Systeme und mobiles Infotainment von Bedeutung. Holographische 3D-Displays, die auf einer, in der Bandbreite limitierten Rekonstruktion von Wellenfrontsegmenten beruhen, profitieren von der spezifischen Charakteristik dicker holographischer Gitter, welche als Bragg-Beugung basierte Volumengitter bezeichnet werden können. Es wird beschrieben, wie die Winkel-, Wellenlängen- und Polarisationsselektivität ausgelegt werden kann, um spezifische optische Funktionalitäten bereitzustellen. Diese sind unter anderem notwendig, um HD-fähige holographische 3D-Displays zu realisieren. Es wird eine kurze Einführung zu Hintergrundbeleuchtungseinheiten, komplexwertigen räumlichen Modulatoren und kombinierten Feldlinsen von holographischen 3D-Displays gegeben. Die Beschreibung Bragg-Beugung basierter Volumengitter erfolgt unter Nutzung der CWT (coupled wave theory). Es wird dargelegt, wie das 2-te Maximum der on-Bragg Modulation genutzt werden kann. Der Vorzug der 2-ten Bragg-Beugungsordnung wird erklärt. Polarisations-Strahlteiler-Geometrien werden beschrieben. Spezifische Anordnungen von holographischen 3D-Displays werden erklärt. Beleuchtungseinheiten und kombinierte Feldlinsen werden untersucht. Es wird beschrieben, wie die Unterdrückung diffraktiven Übersprechens erreicht werden kann.
Patent
  • Gerald Fütterer
Beam Divergence and Various Collimators for Holgraphic or Stereoscopic Displays
  • 2016
Patent
  • Gerald Fütterer
Light Modulation Device
  • 2016
The invention relates to a light modulation device (60) for a display device (10), in particular a holographic display device, for the representation of two-dimensional and/or three-dimensional reconstructed scenes. The light modulation device (60) has at least one spatial light modulator (70), having modulation elements, for the modulation of incident light and an optical element (80) with known optical characteristics. The light falling on the at least one spatial light modulator (70) is thereby sufficiently coherent. The at least one spatial light modulator (70) and the optical element (80) are combined with one another in such a way that the optical element (80) scatters the unmodulated light emitted from the spatial light modulator (70) into an angle range.
Patent
  • Gerald Fütterer
Light Modulation Device
  • 2016
The invention relates to a light modulation device (60) for a display device (10), in particular a holographic display device, for the representation of two-dimensional and/or three-dimensional reconstructed scenes. The light modulation device (60) has at least one spatial light modulator (70), having modulation elements, for the modulation of incident light and an optical element (80) with known optical characteristics. The light falling on the at least one spatial light modulator (70) is thereby sufficiently coherent. The at least one spatial light modulator (70) and the optical element (80) are combined with one another in such a way that the optical element (80) scatters the unmodulated light emitted from the spatial light modulator (70) into an angle range.
Contribution
  • Gerald Fütterer
Field lens multiplexing in holographic 3D displays by using Bragg diffraction based volume gratings
  • 2016
Patent
  • Gerald Fütterer
  • R. Haussler
  • B. Kroll
  • N. Leister
  • S. Reichelt
Combined Light Modulation Device for Tracking Users
  • 2016
Contribution
  • Gerald Fütterer
From Holographic displays to Volume Gratings and Off-Axis Parabolic Mirrors
  • 2016

DOI: 10.1117/12.2245183

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.
JournalArticle
  • Gerald Fütterer
Enabling Holographic 3D Displays with Bragg Diffraction Based Volume Gratings and First Approaches to the Reduction of Diffractive Cross Talk
  • 2016

DOI: 10.25929/276j-2q41

Photonics products often require enhanced optical functionality, which cannot be provided by state of the art optics. This is the case when high-end optical systems as for example holographic 3D displays are developed. Implementation of Bragg diffraction based volume gratings enables small form factor and high definition (HD) natural viewing experience of 3D objects. This is important for modeling 3D data, prototyping, CAD-CAM, computer-integrated manufacturing (CIM), global 3D teleconferencing and mobile infotainment. For example, holographic 3D displays, which are based on space bandwidth limited wave segment reconstruction, profit from the specific characteristics of thick hologram gratings, which can be referred to as Bragg diffraction based volume gratings. It is explained how to adapt angular, spectral and polarization selectivity in order to provide specific optical functionality, which is mandatory in order to realize HD holographic 3D displays. A short introduction to backlight units (BLU), complex valued spatial light modulators (C-SLM) and combined field lenses (cFL) of holographic 3D displays is given. The description of Bragg diffraction based volume gratings is based on the coupled wave theory (CWT). The usage of the 2nd on-Bragg maximum modulation is described. The advantage of the 2nd Bragg diffraction order is explained. Polarization beam splitter (PBS) geometries are described. Specific layouts of holographic 3D displays are explained. BLU and cFL are evaluated. It is shown how the suppression of diffractive crosstalk can be obtained. Oftmals benötigen neue Produkte der Photonik eine erweiterte optische Funktionalität, die nicht von optischen Standard-Komponenten bereitgestellt werden kann. Dies ist auch für die Entwicklung von holographischen 3D-Displays der Fall. Hierbei ermöglicht die Implementierung von Volumengittern, die auf der Bragg-Beugung basieren, eine kompakte Bauweise und eine natürliche Wahrnehmung von 3D-Objekten in HD-Auflösung. Dies ist für die Modellierung von 3D-Daten, die Erstellung von Prototypen, CAD-CAM, Computer integrierte Fertigung (CIM), weltweit arbeitende Telekonferenz-Systeme und mobiles Infotainment von Bedeutung. Holographische 3D-Displays, die auf einer, in der Bandbreite limitierten Rekonstruktion von Wellenfrontsegmenten beruhen, profitieren von der spezifischen Charakteristik dicker holographischer Gitter, welche als Bragg-Beugung basierte Volumengitter bezeichnet werden können. Es wird beschrieben, wie die Winkel-, Wellenlängen- und Polarisationsselektivität ausgelegt werden kann, um spezifische optische Funktionalitäten bereitzustellen. Diese sind unter anderem notwendig, um HD-fähige holographische 3D-Displays zu realisieren. Es wird eine kurze Einführung zu Hintergrundbeleuchtungseinheiten, komplexwertigen räumlichen Modulatoren und kombinierten Feldlinsen von holographischen 3D-Displays gegeben. Die Beschreibung Bragg-Beugung basierter Volumengitter erfolgt unter Nutzung der CWT (coupled wave theory). Es wird dargelegt, wie das 2-te Maximum der on-Bragg Modulation genutzt werden kann. Der Vorzug der 2-ten Bragg-Beugungsordnung wird erklärt. Polarisations-Strahlteiler-Geometrien werden beschrieben. Spezifische Anordnungen von holographischen 3D-Displays werden erklärt. Beleuchtungseinheiten und kombinierte Feldlinsen werden untersucht. Es wird beschrieben, wie die Unterdrückung diffraktiven Übersprechens erreicht werden kann.
Patent
  • Gerald Fütterer
  • B. Kroll
  • N. Leister
  • H. Stolle
Projection display and method for displaying at least one of two-dimensional and three-dimensional scene or of content
  • 2015
Patent
  • Gerald Fütterer
Display Device for Holographic Reconstruction
  • 2015
Patent
  • Gerald Fütterer
  • B. Kroll
  • N. Leister
  • H. Stolle
Projektionsvorrichtung und Verfahren zum Darstellen einer zweidimensionalen und/oder dreidimensionalen Szene oder von Inhalt
  • 2015
Patent
  • Gerald Fütterer
Display Device for Holographic Reconstruction
  • 2015
Patent
  • Gerald Fütterer
Anzeigevorrichtung für eine holografische Rekonstruktion
  • 2015
Patent
  • Gerald Fütterer
Anzeigevorrichtung für eine holografische Rekonstruktion
  • 2015
Patent
  • Gerald Fütterer
  • B. Kroll
  • N. Leister
  • H. Stolle
Projection display and method for displaying at least one of two-dimensional and three-dimensional scene or of content
  • 2015
Patent
  • Gerald Fütterer
  • B. Kroll
  • N. Leister
  • H. Stolle
Projektionsvorrichtung und Verfahren zum Darstellen einer zweidimensionalen und/oder dreidimensionalen Szene oder von Inhalt
  • 2015
Patent
  • Gerald Fütterer
Optisches System zur Messung der Polarisation und der Phase (Inhalt: Verfahren und Anordnungen zur flächigen optischen Darstellung von Ladungsträgern, ihrer Verteilungen und ihrer Beweglichkeit)
  • 2014
Patent
  • Gerald Fütterer
Optisches System zur Messung der Polarisation und der Phase (Inhalt: Verfahren und Anordnungen zur flächigen optischen Darstellung von Ladungsträgern, ihrer Verteilungen und ihrer Beweglichkeit)
  • 2014
Patent
  • Gerald Fütterer
  • R. Häußler
  • B. Kroll
  • N. Leister
  • S. Reichelt
Combined light modulation device for tracking users
  • 2011
Lecture
  • Gerald Fütterer
  • N. Leister
  • R. Haussler
  • S. Reichelt
  • C. Erler
Small Form Factor for Holographic 3D Display Product
  • 2011
Lecture
  • Gerald Fütterer
  • N. Leister
  • R. Haussler
  • S. Reichelt
  • C. Erler
Small Form Factor for Holographic 3D Display Product
  • 2011
Patent
  • Gerald Fütterer
Beam divergence and various collimators for holographic or stereoscopic displays
  • 2011
Patent
  • Gerald Fütterer
  • R. Häußler
  • B. Kroll
  • N. Leister
  • S. Reichelt
Combined light modulation device for tracking users
  • 2011
Patent
  • Gerald Fütterer
Beam divergence and various collimators for holographic or stereoscopic displays
  • 2011
Lecture
  • Gerald Fütterer
Compact Holographic Display Product Solutions Invited Talk
  • 2010
Lecture
  • Gerald Fütterer
Compact Holographic Display Product Solutions Invited Talk
  • 2010
Contribution
  • Gerald Fütterer
Simulation of the detectors response of an autocollimator , volArt. No. 661703
  • 2007
Contribution
  • R. Probst
  • Gerald Fütterer
  • J. Illemann
  • J. Mokroš
  • P. Lui
  • E. Bachish
An angular reversal technique for error separation between a dual axis electronic autocollimator and a PZT tilting platform
  • 2007
Contribution
  • Gerald Fütterer
Simulation of the detectors response of an autocollimator , volArt. No. 661703
  • 2007
Contribution
  • R. Probst
  • Gerald Fütterer
  • J. Illemann
  • J. Mokroš
  • P. Lui
  • E. Bachish
An angular reversal technique for error separation between a dual axis electronic autocollimator and a PZT tilting platform
  • 2007
Patent
  • Gerald Fütterer
Verfahren zur interferometrischen Bestimmung einer optischen Weglänge zwischen der Oberfläche eines Objekts und einer Referenzfläche und Interferometeranordnung
  • 2006
Patent
  • Gerald Fütterer
Verfahren zur interferometrischen Bestimmung einer optischen Weglänge zwischen der Oberfläche eines Objekts und einer Referenzfläche und Interferometeranordnung
  • 2006
Contribution
  • Gerald Fütterer
Enhancement of high-resolution electronic autocollimators by application of phase grating technology
  • 2005

DOI: 10.1117/12.612745

Patent
  • Gerald Fütterer
Autokollimationsfernrohr und Verfahren zur Abbildung einer Messmarke hierfür
  • 2005
Contribution
  • Gerald Fütterer
Enhancement of high-resolution electronic autocollimators by application of phase grating technology
  • 2005

DOI: 10.1117/12.612745

Patent
  • Gerald Fütterer
Autokollimationsfernrohr und Verfahren zur Abbildung einer Messmarke hierfür
  • 2005