Caustic surface produced by a plane wavefront refracted through positive bi-conic lenses

摘要

We study the formation of caustic surfaces produced by bi-conic lenses, considering a plane wavefront propagating parallel to the optical axis. We have already seen that the shape of caustic surfaces can represent the monochromatic aberrations that we call image errors, furthermore the shape of the caustic can be modified by changing the parameters of the lens in such a way that if we are able to vanish the caustic, the optical system produces an image without spherical aberration, alternatively caustic surfaces having a large area could be applied to design non-imaging optical systems, such as diffusers of light. The shape of the caustic surface is a function of the indices of refraction involved in the process of refraction, and all the parameters of the bi-conic lens. We provide an analytic equation for the caustic surface in a meridional plane and some examples are presented.