Paper 14109-600
Paper 14109-600
Multi-LED illumination: from freeform optics design to spectroscopic sensing (Plenary Presentation)
14 April 2026 • 09:05 - 09:50 CEST | Auditorium Erasme (Niveau/Level 0)
Abstract
LED-based illumination has become increasingly attractive for spectroscopy, imaging, and sensing applications due to its spectral diversity and compact form factor. However, efficiently combining the emission of multiple LEDs into a single, well-defined output remains a significant optical design challenge. The spatial and angular overlap of multiple LED sources often results in substantial étendue mismatch, non-uniform illumination, and reduced optical efficiency. In this work, we present an overview of recent advances in the optical design of multi-LED systems, from state-of-the-art methodologies to a novel, compact illumination architecture that employs a single freeform mirror to collect and combine the LED emission beams.
Presenter
Vrije Univ. Brussel (Belgium)
Lien Smeesters is a professor at B-PHOT Brussels Photonics, at the Faculty of Engineering of the Vrije Universiteit Brussel (VUB). Lien focuses on multidisciplinary research in the field of optical design and optical spectroscopy, pursuing the development of novel spectroscopic detection systems. She investigates the full supply chain, starting from the optimization of the spectroscopic sensing technology, and the advanced optical design of the illumination and detection system, benefitting from freeform optics, to a proof-of-concept demonstrator. Lien is coordinating and working on applied-oriented research projects in collaboration with industry, via bilateral collaborations, and within the European Commission funded PhotonHub programme.