Optical simulation of phosphor layer of white LEDs

A Matlab (2009a) program was developed to simulate the photons emitted by the LED chips. The photons' transmission, reflection, and refraction in phosphor layers with different shapes were calculated in this program. The CCT was calculated at different emergent angles with different layer profiles, such as planar layer, hemispherical layer (with different diameters), half ellipsoid layer and other irregular shapes. As a consequence of optimization of angular color uniformity, the trend of configuration of the phosphor layer was discussed and analyzed.