Simulation of the Ronchi test for arbitrary wave aberrations in imaging systems

Abstract

The Ronchi test is a simple qualitative method to identify aberrations in imaging systems: a binary grating is superimposed on its own image formed by the system to produce patterns, known as Ronchigrams, that manifest the aberrations in the system. In practice, the experimentally recorded Ronchigrams are compared with model-based simulations to infer the types and amounts of wave aberrations. In this article an effective algorithm to simulate the Ronchigrams in an imaging system under arbitrary third-order wave aberrations is introduced. The method uses simple coordinate interpolation to transfer the grating transmittance from the object to the image space. High-quality Ronchigrams for all types of wave aberrations can easily be produced. For demonstration purposes, experimental Ronchigrams obtained in real imaging systems are also provided and compared with the simulations. The results show that this technique can both be used as an educational tool, and also in a real test setup.