Heuristic models for diffraction by some simple micro-objects

Electromagnetic optics is normally expected to be the only appropriate approach to describe structures with features of just a few wavelengths. But in some cases, these structure can be well described by simple heuristic arguments relying on geometrical optics and on diffraction by known elementary primitives. Such an approach allows a better understanding of the involved physical phenomena and reduces the computation time. We investigate the case of a microcomponent with a triangular section by using two approximate models with increasing complexity and explore their limits as the size of the structure decreases. Results are compared with a rigorous electromagnetic approach and discussed on the basis of near-field and far-field diffraction patterns.