Geometrical Optics Reloaded
Event details
| Date | 06.02.2015 |
| Hour | 14:00 |
| Speaker | Prof. Frank Wyrowski, University of Jena, Germany |
| Location |
Microcity: MC B1 303
|
| Category | Conferences - Seminars |
Organised by Optics and Photonics Technology Lab, Microcity
Geometrical and wave optics are commonly considered as opposite poles in optical modeling. In ray tracing, geometrical optics is used to propagate rays through systems and in wave optics, complex amplitudes are propagated by diffraction integrals and other techniques. Historically the light representation by rays versus complex amplitudes is closely connected to the use of geometrical optics versus diffraction integrals for light propagation. Often it is concluded, that geometrical optics does not include phenomena like diffraction, interference, coherence, and polarization. The quite popular distinction between scalar and electromagnetic waves does not make the situation more comprehensible.
We like to discuss geometrical optics from a more general point of view, which in fact was already suggested by Born and Wolf in 1959 in their classic book Principles of Optics. We follow them and understand geometrical optics as an approximate solution of Maxwell’s equations that is often very accurate in practice. By this application of geometrical optics to electromagnetic fields instead of rays, it becomes obvious, that geometrical optics can model interference, partial coherence and polarization effects to a large extent, but excludes diffraction effects. Thereby, we understand diffraction effects in a quite wide sense, which is discussed along a global and local plane wave decomposition of electromagnetic fields. Geometrical optics for electromagnetic fields can be nicely combined with other solutions of Maxwell’s equations, rigorous and approximate ones, in order to provide a unified modeling concept for optical systems, to which we refer to as field tracing.
In the talk, we start with a comparison of ray and field tracing concepts as well as its pros and cons for optical modeling and design. Special emphasis is given to geometrical optics for electromagnetic fields. That includes a discussion of a serious weakness of ray tracing, namely its low convergence in lighting and scattering modeling. It turns out, that field tracing does not only provide higher modeling accuracy, but often also higher modeling speed.
Various modeling examples are presented in the talk by demonstrations with the optics software VirtualLab. Examples include freeform surfaces, multimode fiber coupling, and imaging.
Geometrical and wave optics are commonly considered as opposite poles in optical modeling. In ray tracing, geometrical optics is used to propagate rays through systems and in wave optics, complex amplitudes are propagated by diffraction integrals and other techniques. Historically the light representation by rays versus complex amplitudes is closely connected to the use of geometrical optics versus diffraction integrals for light propagation. Often it is concluded, that geometrical optics does not include phenomena like diffraction, interference, coherence, and polarization. The quite popular distinction between scalar and electromagnetic waves does not make the situation more comprehensible.
We like to discuss geometrical optics from a more general point of view, which in fact was already suggested by Born and Wolf in 1959 in their classic book Principles of Optics. We follow them and understand geometrical optics as an approximate solution of Maxwell’s equations that is often very accurate in practice. By this application of geometrical optics to electromagnetic fields instead of rays, it becomes obvious, that geometrical optics can model interference, partial coherence and polarization effects to a large extent, but excludes diffraction effects. Thereby, we understand diffraction effects in a quite wide sense, which is discussed along a global and local plane wave decomposition of electromagnetic fields. Geometrical optics for electromagnetic fields can be nicely combined with other solutions of Maxwell’s equations, rigorous and approximate ones, in order to provide a unified modeling concept for optical systems, to which we refer to as field tracing.
In the talk, we start with a comparison of ray and field tracing concepts as well as its pros and cons for optical modeling and design. Special emphasis is given to geometrical optics for electromagnetic fields. That includes a discussion of a serious weakness of ray tracing, namely its low convergence in lighting and scattering modeling. It turns out, that field tracing does not only provide higher modeling accuracy, but often also higher modeling speed.
Various modeling examples are presented in the talk by demonstrations with the optics software VirtualLab. Examples include freeform surfaces, multimode fiber coupling, and imaging.
Practical information
- General public
- Free
Organizer
- Hans Peter Herzig
Contact
- Khan Brigitte [[email protected]]