Directional and angle-resolved optical scattering of high-performance translucent polymer sheets for energy-efficient lighting and skylights.

Transparent refractive-index matched micro (TRIMM) particles have proved to be an excellent scattering component for use in translucent sheets. Measurements of hemispheric transmittance and reflectance versus angle of incidence, as well as angle-resolved studies of such translucent sheets, have been carried out to complement earlier published hemispheric reflectance and transmittance spectral measurements carried out at normal angle of incidence. Hemispheric values relative to angle of incidence are of interest for daylighting applications and building simulations, and angle-resolved measurements are vital for verifying that our modeling tools are reliable. Ray-tracing simulations based on Mie scattering for the individual TRIMM particles and angle-resolved measurements are in good agreement, indicating that the simulation method used is practical for the design of new scattering profiles by varying particle concentration or refractive index.