Approximate analytical optical transfer function for a wavefront-coded imaging system with two-dimensional rectangularly separable phase masks

摘要

Abstract. Wavefront coding can be used to extend the depth of field ofnincoherent imaging systems and is a powerful system-level technique. Innorder to assess the performance of a wavefront-coded imaging system,ndefocused optical transfer function u0001OTFu0002 is the metric frequently used.nUnfortunately, to the best of our knowledge, among all types of phasenmasks, it is usually difficult to obtain the analytical OTF except the cubicnone. Although numerical computation seems good enough for perfor-nmance evaluation, the approximate analytical OTF is still indispensablenbecause it can reflect the relationship between mask parameters andnsystem frequency response in a clearer way. Thus, a method is pro-nposed to derive the approximate analytical OTF for two-dimensional rect-nangularly separable phase masks. The analytical results are well consis-ntent with the direct numerical computations, but the proposed methodncan be accepted only from engineering point of view and needs rigorousnproof in future. © 2010 Society of Photo-Optical Instrumentation Engineers.nu0003DOI: 10.1117/1.3485759