Reflectors for efficient and uniform distribution of radiation for lighting and infrared based on non-imaging optics

Wen Cai, Jeff M. Gordon, Peter Kashin, Ari Rabl

    Research output: Contribution to journalConference articlepeer-review


    A fundamental problem in illumination optics, with important applications for lighting and infrared heating, is to design reflectors that can concurrently fulfill two conditions: (1) maximum efficiency (all rays from the source reach the target); (2) uniform flux density on the target plane. The problem is difficult when the source is extended (rather than a point or a line) and when the reflector must be small compared to target distance and target size, i. e. when the field of view subtends a large angle. In general an exact solution is impossible with a finite number of optical elements. To find practical solutions that approach the goal, we take the Compound Parabolic Concentrator (CPC) of non-imaging optics as a starting point because it achieves the first condition by its very design. However, its flux density distribution falls off like cos3(θ) where 9 is the angle from the normal of the aperture. To gain an extra degree of freedom for the design, we modify the CPC by introducing a gap between source and reflector. We present results for symmetrical configurations in two dimensions (troughlike reflectors) for flat and for tubular sources. For fields of view of practical interest (half angle in the range of 40 to 60°), these devices can achieve minimum-to-maximum intensity ratios of around 0.7, while remaining compact and incurring low reflective losses.

    Original languageEnglish
    Pages (from-to)118-128
    Number of pages11
    JournalProceedings of SPIE - The International Society for Optical Engineering
    StatePublished - 24 Oct 1991
    EventNonimaging Optics: Maximum Efficiency Light Transfer 1991 - San Diego, United States
    Duration: 21 Jul 1991 → …

    ASJC Scopus subject areas

    • Electronic, Optical and Magnetic Materials
    • Condensed Matter Physics
    • Computer Science Applications
    • Applied Mathematics
    • Electrical and Electronic Engineering


    Dive into the research topics of 'Reflectors for efficient and uniform distribution of radiation for lighting and infrared based on non-imaging optics'. Together they form a unique fingerprint.

    Cite this