An Innovative Method to Treat Very Small Apertures in Ray-Tracing Simulations

This work addresses a specific type of configurations where typical ray-tracing simulations can fail to produce meaningful results, namely when the light intensity transmitted by a very small aperture needs to be determined. In such cases it is indeed computational very expensive, if not prohibitive, to simulate all the rays that are needed in order to get a statistically significant number through the aperture. Our proposed solution exploits a virtual source to intrinsically limit the simulation only to those rays that do cross the aperture thus, massively enhancing the computational efficiency. We lay down the mathematical formalism behind the method and present it also in the form of a simple, generalizable algorithm. Finally, we provide an experimental test that confirms the validity of our proposal across a range of aperture sizes.