Illumination design with virtually reflecting/refracting surfaces

ABSTRACT We propose an easy-to-handle method of surface parameterization which is valuable for enhancing the illumination design process. Therefore, an additional normal vector function is provided defining the desired direction of the virtual normal vector at each point of the surface. Hence, the reflection/refraction properties are seperated from the shape of the surface. These surfaces are named Virtually Reflecting/Refracting Surfaces (VRS). This type of surface provides the opportunity to alter the normal direction without changing the shape of the surface and vice versa. Therefore, the designer can have a selective look at those quantities depending mainly on position or on direction. This means that, e.g., one can first prescribe the geometrical shape and adjust the surface’s optical properties afterwards. Moreover, structured surfaces, e.g., segmented reflectors, can be replaced in between by virtually reflecting surfaces in order to eliminate discontinuities. This is apparently expedient for improving the convergence in automatic design. We investigate optical layouts with VRS to demonstrate their impact on the design and the optimization process. Keywords: optical design, illumination design, surface parameterization, VRS 1.