22 August 2005 Characterization of the thermodynamic quality of light sources
Author Affiliations +
The edge ray theorem has become a tenet for illumination design. For idealized configurations this theorem has proved extremely powerful and has led to new methods of design. However, many real life sources have no clean delimitation and thus the boundary of the phase space is not easy to specify. Optical efficiency expressed by the fraction of the light captured by the optical system and transferred to the target on one hand and average radiance at the target on the other hand become two conflicting objectives in illumination design. Optimal design generally requires a single scalar merit function. Two different objectives require a metric which specifies the relative valuation before optimality may even be defined. In practice the relative valuation depends on the application and seldom may be specified in advance. It is, however, possible to refer to a slightly weaker criterion, called pareto-optimality which allows to postpone the decision on the relative valuation. In this contribution we show how to derive the upper limits of efficiency and average radiance for all paretooptimal illumination designs using a given source. If an optical system observes the edge ray principle such that the boundary of the source follows a iso-radiance hyper-surface in phase space, then this system is pareto-optimal. To calculate the characteristic curve one needs to sort phase space according to radiance. We show an example of an illumination lens which was inspired by phase space sorting. We have found this tool extremely useful because it allows to outline the range of options before actually embarking on the optical design.
© (2005) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Julius Muschaweck, Harald Ries, "Characterization of the thermodynamic quality of light sources", Proc. SPIE 5942, Nonimaging Optics and Efficient Illumination Systems II, 594206 (22 August 2005); doi: 10.1117/12.615874; https://doi.org/10.1117/12.615874


A novel solution for LED wall lamp design and simulation
Proceedings of SPIE (November 06 2014)
Novel non-imaging optic design for uniform illumination
Proceedings of SPIE (March 04 2016)
Curved shadow generation by ray tracing in the plane
Proceedings of SPIE (September 01 1990)
Light Emitting Diodes As Short Duration Light Sources
Proceedings of SPIE (July 27 1979)
Backward modelling of LED primary optics
Proceedings of SPIE (September 09 2010)
Optical design using luminance in ray data sets
Proceedings of SPIE (October 11 2012)

Back to Top