Precise optical modeling of blue light-emitting diodes by Monte Carlo ray-tracing.

Precise optical modeling of blue light-emitting diodes (LEDs) is constructed by reasonable optical parameters and Monte Carlo ray-tracing with the capability of precisely predicting light extraction and radiation pattern for both bare LED and packaged LED. Refractive indices and absorption coefficients of LED materials are determined by abundant references and comparisons between simulations and experiments. Surface roughness is considered in the optical model to improve the simulation precision. The simulation precisions are excellent for both bare blue LEDs (>96.5% for light extraction and >99% for radiation pattern) and packaged blue LEDs (>98.5% for both light extraction and radiation pattern).