Mr. Julius A. Muschaweck Profile

Julius A. Muschaweck

CEO at JMO GmbH

SPIE Involvement:

Area of Expertise:

Optical Design for Illumination , LEDs , Matlab , C++ , LightTools

Websites:

Company Website

I am a German physicist, and have been working on optical design for illumination for over twenty years. After a stay as Visiting Scholar at the University of Chicago with Prof. Roland Winston (well known as the originator of Nonimaging Optics), I was co-founder and CEO of OEC, an optical engineering service which pioneered freeform optics. Later, at OSRAM, where I held the position of Senior Principal Key Expert (the highest rank in the OSRAM/Siemens expert career), I coordinated the over 100 optical designers within OSRAM world-wide. I then joined ARRI, the leading movie camera and lamp head maker, as Principal Optical Scientist. Now, I am working as an independent consultant, providing illumination optics solutions to industry clients, teaching courses on illumination optics, and writing about the subject. I am is the author of over 25 scientific papers and the inventor of over 50 patent applications.
It is not only the surprising depth, and mathematical beauty, of illumination optics that continues to fascinate me after over 20 years in the field. What really strikes me as unique is that is beautiful, deep theory allows us to derive strong statements about what is possible, and what is impossible in our daily work as optical designers.

Proceedings Article | 14 September 2023 Paper

Phase space diagrams in illumination optics

Henning Rehn, Julius Muschaweck

Proceedings Volume 12798, 127980H (2023) https://doi.org/10.1117/12.2691622

KEYWORDS: Light sources and illumination, Geometrical optics, Inhomogeneities, Monochromatic aberrations, Telescopes, Rods, Reflection

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Proceedings Article | 14 September 2023 Paper

Illumination design problem: the unicorn’s horn

William Cassarly, Julius Muschaweck, Henning Rehn, John Koshel, Lien Smeesters

Proceedings Volume 12798, 127980J (2023) https://doi.org/10.1117/12.3005730

KEYWORDS: Design and modelling, Light sources and illumination, Waveguides, Solids, Prisms, Hollow waveguides, Optical design, Total internal reflection, Refraction, Reflection

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SPIE Journal Paper | 26 July 2023

Virtual focus of a ray data source

Julius Muschaweck

OE, Vol. 62, Issue 07, 070401, (July 2023) https://doi.org/10.1117/12.10.1117/1.OE.62.7.070401

KEYWORDS: Light emitting diodes, Matrices, Collimation, Optical engineering, Light sources and illumination, Light sources, Optical design, Data modeling, Lamps, Collimators

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Proceedings Article | 3 October 2022 Presentation + Paper

Tailored freeform surfaces for illumination with extended sources

Julius Muschaweck

Proceedings Volume 12220, 1222004 (2022) https://doi.org/10.1117/12.2632439

KEYWORDS: Wavefronts, Freeform optics, Light sources and illumination, Ray tracing, Light emitting diodes, Light, Complex systems, Refractive index

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Proceedings Article | 3 October 2022 Paper

What light tubes are good for: connecting theories

Henning Rehn, Julius Muschaweck

Proceedings Volume 12220, 1222002 (2022) https://doi.org/10.1117/12.2631710

KEYWORDS: Geometrical optics, Light emitting diodes, Optical design, Ray tracing, Imaging systems, Solar concentrators, Projection systems

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SPIE Press Book | 13 April 2022

Designing Illumination Optics

Julius Muschaweck, Henning Rehn

KEYWORDS: Light emitting diodes, Reflectors, Light, Optical design, Imaging systems, Tolerancing, Nonimaging optics, Projection systems, Lamps, Geometrical optics

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Proceedings Article | 19 November 2021 Paper

IODC 2021 illumination design problem: the curse of Prince Lambert

William Cassarly, Julius Muschaweck, Henning Rehn, John Koshel

Proceedings Volume 12078, 120781Z (2021) https://doi.org/10.1117/12.2605496

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Proceedings Article | 12 September 2021 Presentation + Paper

Modeling real life LED spectra from data sheet information only

Julius Muschaweck

Proceedings Volume 11874, 118740B (2021) https://doi.org/10.1117/12.2601775

KEYWORDS: Light emitting diodes, Data modeling, RGB color model, Blue light emitting diodes, Spectral models, MATLAB, Process control, Indium gallium nitride, Thermal modeling, Temperature metrology, Colorimetry

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SPIE Journal Paper | 27 October 2018 Open Access

Special Section Guest Editorial: Advances in Optical Design

Peter Clark, Julius Muschaweck, Richard Pfisterer, John Rogers

OE, Vol. 57, Issue 10, 101700, (October 2018) https://doi.org/10.1117/12.10.1117/1.OE.57.10.101700

KEYWORDS: Optical design, Optical engineering, Optics manufacturing, Software development, Optical testing, Imaging systems, Biomedical optics, Lens design, Optical fabrication, Cameras

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Proceedings Article | 30 September 2013 Paper

Data format standard for sharing light source measurements

G. Groot Gregory, Ian Ashdown, Willi Brandenburg, Dominique Chabaud, Oliver Dross, Sanjay Gangadhara, Kevin Garcia, Michael Gauvin, Dirk Hansen, Kei Haraguchi, Günther Hasna, Jianzhong Jiao, Ryan Kelley, John Koshel, Julius Muschaweck

Proceedings Volume 8835, 88350D (2013) https://doi.org/10.1117/12.2021670

KEYWORDS: Computer aided design, Light sources, Data modeling, Ray tracing, Optical design, Light emitting diodes, Manufacturing, Binary data, Optical testing, Solid modeling

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Proceedings Article | 18 December 2012 Paper

Estimating the performance of remote phosphor SSL devices by simulations

Ch. Wiesmann, A. Linkov, J. Muschaweck

Proceedings Volume 8550, 85502G (2012) https://doi.org/10.1117/12.2001607

KEYWORDS: Silicon, Solid state lighting, Refractive index, Light scattering, Glasses, Particles, Absorption, Semiconductors, Thermography, Scattering

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Proceedings Article | 11 October 2012 Paper

Optical design using luminance in ray data sets

Julius Muschaweck

Proceedings Volume 8485, 84850P (2012) https://doi.org/10.1117/12.930605

KEYWORDS: Ray tracing, Optical design, Light sources, Lamps, Projection systems, Monte Carlo methods, Mathematical modeling, Optical spheres, Geometrical optics, Optics manufacturing

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Proceedings Article | 21 September 2011 Paper

Optics designs for an innovative LED lamp family system

Herbert Weiss, Julius Muschaweck, Stefan Hadrath, Sergey Kudaev

Proceedings Volume 8170, 81700M (2011) https://doi.org/10.1117/12.903050

KEYWORDS: Lamps, Light emitting diodes, LED lighting, Diffusers, Light sources and illumination, Floods, Optical design, Collimation, Light sources, Reflectors

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Proceedings Article | 21 September 2011 Paper

What's in a ray set: moving towards a unified ray set format

Julius Muschaweck

Proceedings Volume 8170, 81700N (2011) https://doi.org/10.1117/12.896757

KEYWORDS: Ray tracing, Binary data, Light sources, Near field, Optics manufacturing, Monte Carlo methods, Optical design, Near field optics, Optical simulations, Polarization

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For the purpose of optical simulation, a plethora of formats exist to describe the properties of a light source. Except for the EULUMDAT and IES formats which describe sources in terms of aperture area and far field intensity, all these formats are vendor specific, and no generally accepted standard exists. Most illumination simulation software vendors use their own format for ray sets, which describe sources in terms of many rays. Some of them keep their format definition proprietary. Thus, software packages typically can read or write only their own specific format, although the actual data content is not so different. Typically, they describe origin and direction of each ray in 3D vectors, and use one more single number for magnitude, where magnitude may denote radiant flux, luminous flux (equivalently tristimulus Y), or tristimulus X and Z. Sometimes each ray also carries its wavelength, while other formats allow to specify an overall spectrum for the whole source. In addition, in at least one format, polarization properties are also included for each ray. This situation makes it inefficient and potentially error prone for light source manufacturers to provide ray data sets for their sources in many different formats. Furthermore, near field goniometer vendors again use their proprietary formats to store the source description in terms of luminance data, and offer their proprietary software to generate ray sets from this data base. Again, the plethora of ray sets make the ray set production inefficient and potentially error prone. In this paper, we propose to describe ray data sets in terms of phase space, as a step towards a standardized ray set format. It is well known that luminance and radiance can be defined as flux density in phase space: luminance is flux divided by etendue. Therefore, single rays can be thought of as center points of phase space cells, where each cell possesses its volume (i.e. etendue), its flux, and therefore its luminance. In addition, each phase space cell possesses its spectrum, and its polarization properties. We show how this approach leads to a unification of the EULUMDAT/IES, ray set and near field goniometer formats, making possible the generation of arbitrarily many additional rays by luminance interpolation. We also show how the EULUMDAT/IES and individual ray set formats can be derived from the proposed general format, making software using a possible standard format downward compatible.

Proceedings Article | 9 February 2011 Paper

Randomized micro lens arrays for color mixing

Julius Muschaweck

Proceedings Volume 7954, 79540A (2011) https://doi.org/10.1117/12.877219

KEYWORDS: Light emitting diodes, Scattering, Beam shaping, Laser scattering, Spherical lenses, Collimation, Mirrors, Light scattering, Solids, General lighting

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Proceedings Article | 2 September 2010 Paper

Primary optics for LEDs: state of the art of optical architectures

Julius Muschaweck, Peter Brick, Stefan Grötsch, Simon Schwalenberg

Proceedings Volume 7652, 765209 (2010) https://doi.org/10.1117/12.868632

KEYWORDS: Light emitting diodes, Optics manufacturing, Near field optics, Compound parabolic concentrators, Tolerancing, Lenses, Photonic crystals, Optical design, Silicon, Domes

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Proceedings Article | 22 August 2005 Paper

Characterization of the thermodynamic quality of light sources

Julius Muschaweck, Harald Ries

Proceedings Volume 5942, 594206 (2005) https://doi.org/10.1117/12.615874

KEYWORDS: Light emitting diodes, Lamps, Light sources, Optical spheres, Thermodynamics, Photography, Ray tracing, Ceramics, Optical design, Visualization

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SPIE Journal Paper | 1 July 2004

Optimized additive mixing of colored light-emitting diode sources

Harald Ries, Ines Leike, Julius Muschaweck

OE, Vol. 43, Issue 07, (July 2004) https://doi.org/10.1117/12.10.1117/1.1753273

KEYWORDS: Light emitting diodes, Light sources, Lamps, Light, Manufacturing, Optical engineering, Luminous efficiency, Quantum efficiency, Eye, Visualization

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Proceedings Article | 12 November 2003 Paper

Complex 3D-tailored facets for optimal lighting of facades and public places

Wilfried Pohl, Christian Anselm, Christian Knoflach, Andreas Timinger, Julius Muschaweck, Harald Ries

Proceedings Volume 5186, (2003) https://doi.org/10.1117/12.508383

KEYWORDS: Light sources and illumination, Light sources, Mirrors, Visualization, Lamps, Light, Aluminum, Reflectors, Optical design, 3D acquisition

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Proceedings Article | 12 November 2003 Paper

Mixing colored LED sources

Harald Ries, Ines Leike, Julius Muschaweck

Proceedings Volume 5186, (2003) https://doi.org/10.1117/12.509669

KEYWORDS: Light emitting diodes, Lamps, Light sources, Light, Blue light emitting diodes, Solids, Quality measurement, Silver, Luminous efficiency, Visible radiation

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Proceedings Article | 12 November 2003 Paper

Designing tailored free-form surfaces for general illumination

Andreas Timinger, Julius Muschaweck, Harald Ries

Proceedings Volume 5186, (2003) https://doi.org/10.1117/12.505918

KEYWORDS: Mirrors, Light, 3D acquisition, Optical design, Light sources, Light sources and illumination, Optical components, Fluctuations and noise, Visualization, Lamps

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Proceedings Article | 10 December 2001 Paper

Tailoring freeform lenses for illumination

Harald Ries, Julius Muschaweck

Proceedings Volume 4442, (2001) https://doi.org/10.1117/12.449957

KEYWORDS: Ray tracing, Wavefronts, Numerical analysis, Visualization, Lenses, Partial differential equations, Optical design, Monte Carlo methods, Differential equations, Lens design

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Proceedings Article | 6 October 1999 Paper

Double-tailored microstructures

Harald Ries, Julius Muschaweck

Proceedings Volume 3781, (1999) https://doi.org/10.1117/12.368244

KEYWORDS: Reflectors, Geometrical optics, Reflectivity, Eye, Optical properties, Solar concentrators, Imaging systems, 3D acquisition, Optical components, Nonimaging optics

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Proceedings Article | 6 October 1999 Paper

Maximum gap of ideal concentrators for cylindrical absorbers

Harald Ries, Julius Muschaweck

Proceedings Volume 3781, (1999) https://doi.org/10.1117/12.368243

KEYWORDS: Reflectors, Solar concentrators, Reflector design, Chemical elements, Solids, Differential equations, Nonimaging optics, Reflectivity, Vacuum tubes, Light sources

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Proceedings Article | 3 October 1997 Paper

Asymmetrical cone-type secondary concentrators for Fresnel-type reflectors in solar towers

Wolfgang Spirkl, Andreas Timinger, Harald Ries, Abraham Kribus, Julius Muschaweck

Proceedings Volume 3139, (1997) https://doi.org/10.1117/12.279221

KEYWORDS: Reflectors, Solar concentrators, Compound parabolic concentrators, Sun, Ray tracing, Solar energy, Thermodynamics, Receivers, Indium, Nonimaging optics

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Showing 5 of 25 publications

SPIE Conference Volume | 11 December 2017

International Optical Design Conference 2017

SPIE Conference Volume | 20 January 2015

International Optical Design Conference 2014

Conference Committee Involvement (11)

Optical Design and Testing XIV

12 October 2024 | Nantong, Jiangsu, China

Illumination Optics VII

8 April 2024 | Strasbourg, France

Optical Design and Testing XIII

14 October 2023 | Beijing, China

Optical Design and Testing XII

5 December 2022 | Online Only, China

Illumination Optics VI

13 September 2021 | Online Only, Spain

Showing 5 of 11 Conference Committees

Course Instructor

SC1313: Designing Illumination Optics

This course first explains the deep, beautiful, and immensely useful theory of light for illumination: the theory that lets us see what can or cannot be done in illumination optics, and that guides us towards viable solutions. Ètendue, the most mysterious quantity in illumination optics is fully explained and revealed as the most important quantity in illumination optics. Then, the course introduces “design patterns” in illumination optics: optical elements as building blocks, providing reusable solution approaches to recurring problems. These building blocks (e.g., TIR lenses, mixing rods and Köhler illumination) are explained by what they do to the light, and how to combine them. Practical examples as well as exercises with solutions for later self-study are an integral part of the course.

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SC1314: Colorimetry for LED Users

This course first introduces basic concepts of colorimetry, human color vision, the common CIE color spaces, color difference metrics and color rendering metrics. Additive color mixing is what happens when two or more LEDs are combined in a single source. Fortunately, there is an easy to grasp, intuitive visualization of additive color mixing in the common CIE 1931 XYZ color space. Building on this colorimetric foundation, the three major LED families are introduced: InGaN blue-green, InGaAlP yellow-red, and InGaN-plus-phosphor white. The spectral and electrical properties of all three LED families vary from LED to LED, and even for a single LED, with temperature and current. The course shows how these variations can be modeled, for arbitrary operating conditions, from data sheet information only. Finally, the circle back to colorimetry is closed by using some examples to show how to quantitatively compute the colorimetric effects of these LED variations. Throughout the course, practical examples of colorimetric computations and LED modeling are presented, using the instructor’s open source, public domain Matlab® spectrum library.

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