Designing of light-pipe diffuser through its computed optical properties: A novel solution technique and some consequences

Abstract

Light diffusing modules with improved optical properties could usefully facilitate the quest to achieve smart daylight harvesting in office buildings without detrimentally affecting visual comfort in building interiors. However, direct sunlight and sky light may cause discomfort glare. And a use of optically dense diffusers to reduce this effect and produce more uniform indoor light fields is not an efficient solution because of a concomitant loss of luminous energy. Hence, the need for more environment and people sensitive solutions is pressing in order to improve combined optical efficiency, efficacy and ergonomy of work-place luminance.That design aspiration is addressed and involves semitransparent apertures with the directional distribution of luminous intensity approaching that required. Methods for targeted shaping of an illuminance pattern are certainly advantageous for visual comfort, while supporting more demanding visual work and more flexible visual orientation. The numerical experiments we have conducted have proved that retrieval of optimum optical properties of a diffusing medium is possible through minimizing the differences between theoretical and required illuminance patterns. The inverse transform has been successfully validated for sensitivity, specificity and convergence. Our solution is augmented by the proposal for a possible realization of the diffusing aperture in the form of a particle-doped transparent medium which mimics, thus can personalize, the illuminance patterns desired.