Efficient modeling of photonic crystal structures under diffuse light illumination

In order to efficiently model and optimize photonic crystal structures under diffuse light we have to first develop a simulation tool to generate a spatially incoherent source. Here we present a new technique for modeling wide-band spatially incoherent source and implement this technique using finite difference time-domain (FDTD) method. We compare this new method with the conventional method of simulating an incoherent source. We show that this method reduces the computation time by more than one order of magnitude with less than 10% error.