Performance comparison of a freeform lens and a CDTIRO when combined with an LED

Sina Babadi*, Roberto Ramirez-Iniguez, Tuleen Boutaleb, Tapas Mallick

*Corresponding author for this work

    Research output: Contribution to journalArticlepeer-review

    6 Citations (Scopus)
    93 Downloads (Pure)


    This paper compares the features and performance of two secondary optics when combined with an LED. The aim and application of the secondary optic are explained in the introduction section. Sections 2 and 3 introduce two optics: a freeform lens and a novel Circular Dielectric Totally Internally Reflecting Optic (CDTIRO), which can provide uniform illumination. The design process, ray tracing simulations and experimental performance of the freeform lens are described in detail in section 2. The ray tracing simulation and experimental performance of the CDTIRO are presented in section 3. Section 4 presents a comparison of the features of both lenses and their performance. Both optics can produce over 95% uniformity within an illuminated area. However, the uniformity produced by the freeform lens reduces abruptly compared with the CDTIRO when some parameters such as size and the position of the light source are changed.
    Original languageEnglish
    Article number7983349
    JournalIEEE Photonics Journal
    Issue number5
    Early online date18 Jul 2017
    Publication statusPublished - Oct 2017


    • secondary optic
    • freeform lens
    • CDTIRO
    • uniform illumination and LED

    ASJC Scopus subject areas

    • Atomic and Molecular Physics, and Optics
    • Electrical and Electronic Engineering


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