Combining ray-tracing and FDTD to enable the simulation of complex optical devices in an iterative simulation process with reduced simulation effort

The development of photonic multi-scale devices with tailor-made optical properties requires the control and the manipulation of light propagation within structures of different length scales, ranging from sub-wavelength to macroscopic dimensions. Unfortunately, applications of common optical simulation methods are usually restricted to particular size regimes. For this reason, a complete optical simulation of multi-scale devices can only be conducted by combining different simulation methods. In our previous work we already introduced an interface method that uses the Poynting vector to bridge between classical Ray-Tracing and the Finite-Difference-Time-Domain method to enable the simulation of suchlike devices. In this contribution we present and discuss a method to reduce the simulation effort and time consumption of this interface simulation process. This approach is based on an FDTD simulation concept for creating the matrices containing probability density distributions that are needed for the FDTD-RT interface simulations by using broadband frequency sources. With this new FDTD simulation concept, the number of simulations needed to create these matrices can be significantly decreased.