Determination of tailored filter sets to create rayfiles including spatial and angular resolved spectral information Ingo Rotscholl, ∗1 Klaus Trampert, 1 Udo Kr ¨ uger, 2 Martin Perner, 1 Franz Schmidt, 2,3 and Cornelius Neumann 1 1 Light Technology Institute, Karlsruhe Institute of Technology, Engesserstr. 13, 76131 Karlsruhe, Germany 2 TechnoTeam Bildverarbeitung GmbH, Werner-von-Siemens-Strasse 5, 98693 Ilmenau, Germany 3 Graduate School on Image Processing and Image Interpretation, Technical University Ilmenau, Ehrenbergstraße 29, 98693 Ilmenau, Germany ∗ ingo.rotscholl@kit.edu Abstract: To simulate and optimize optical designs regarding perceived color and homogeneity in commercial ray tracing software, realistic light source models are needed. Spectral rayfiles provide angular and spatial varying spectral information. We propose a spectral reconstruction method with a minimum of time consuming goniophotometric near field measure- ments with optical filters for the purpose of creating spectral rayfiles. Our discussion focuses on the selection of the ideal optical filter combination for any arbitrary spectrum out of a given filter set by considering measurement uncertainties with Monte Carlo simulations. We minimize the simulation time by a preselection of all filter combinations, which bases on factorial design. © 2015 Optical Society of America OCIS codes: (120.4820) Optical systems; (350.4600) Optical engineering; (120.5240) Pho- tometry; (120.5630) Radiometry; (220.2945) Illumination design. References and links 1. I. Ashdown, “Near-field photometry: a new approach,” J. Illum. Eng. Soc. 22(1), 163–180(1993). 2. I. Ashdown, and M. Salsbury, “A near-field goniospectroradiometer for LED measurements,” Proc. SPIE 6342, 634215(2007). 3. M.L´ opez, K. Bredemeier, N. Rohrbeck, C. V´ eron, F. Schmidt, and A. Sperling “LED near-field goniophotometer at PTB,” Metrologia 49(2), 141–145(2012). 4. R. Rykowski, “Spectral ray tracing from near field goniophotometer measurements,” Light. Eng. 19(1), 23– 29(2011). 5. OSRAM Opto Semiconductors application note, “Importing rayfiles of LEDs from OSRAM Opto Semicon- ductors”, (OSRAM Opto Semiconductors, 2013), http://www.osram-os.com/Graphics/XPic5/00165120 0.pdf, (accessed, July, 2015). 6. V. Jacobs, J. Audenaert, J. Bleumers, G. Durinck, P. Rombauts, and P. Hanselaer, “Rayfiles including spectral and colorimetric information,” Opt. Express 23(7), A361–A370(2015). 7. V. Jacobs, J. Audenaert, J. Bleumers, G. Durinck, P. Rombauts, and P. Hanselaer, “On spectral ray files of light sources using principal component analysis,” in Proceedings of 28th CIE Session 2015 (CIE, 2015), pp. 543–547. 8. IES,“Ray File Format for the Description of the Emission Property of Light Sources,” TM25-13(2013). 9. F. Reifergeiste and J. Lienig, “Modelling of the temperature and current dependence of LED spectra,” J. Light Vis. Environ. 32(3), 288–294(2008). 10. CVI Laser Optics, “Datasheet selection guide,” pp. 232–233, https://marketplace.idexop.com/store/Support Documents/12 FiltersandEtalons 2013 final-e.pdf, (accessed, July, 2015). #248854 Received 27 Aug 2015; revised 29 Sep 2015; accepted 30 Sep 2015; published 3 Nov 2015 (C) 2015 OSA 16 Nov 2015 | Vol. 23, No. 23 | DOI:10.1364/OE.23.029543 | OPTICS EXPRESS 29543