Design and modeling of a miniature system containing micro-optics

The design and modeling of micro-optical systems is still a challenging task because classical methods like ray tracing do not take into account diffraction effects and other coherent effects which appear e.g. in the presence of micro-optical array systems. On the other side, there exist scalar or rigorous diffraction theories to model optical systems. But they are also limited in their applications because they either neglect non-paraxial effects or the calculation time is too high for a practical use. In this paper we will therefore give an overview about existing (scalar) theories to model optical systems, especially systems containing micro-optics: a simple paraxial matrix theory, ray tracing, Gaussian beam propagation and the propagation of a wave using the angular spectrum of plane waves. The advantages and disadvantages of these theories will be shown and compared. At the end we will describe a combination of ray tracing and wave propagation methods to give a more realistic simulation of micro-optical systems.