Optical performance of coherent and incoherent imaging systems in the presence of ghost images

Ghost image analysis is of interest for optical designers as ghost images may degrade image quality in imaging systems. In a previous paper by Abd El-Maksoud and Sasian [Appl. Opt. 50, 2305 (2011)10.1364/AO.50.002305], ghost image analysis for incoherent systems was evaluated using geometrical optics. Some criteria were presented to identify focused ghost images at the nominal image plane. The main goal of this paper is to provide a conceptual understanding of ghost image formation and its impact on the performance of imaging systems using wave theory and Fourier optics. To achieve this goal, a methodology is developed to model ghost images after considering diffraction effects. Expressions for the ghost diffraction point spread function and the ghost transfer function are presented. These functions are used to construct effective point spread and effective transfer functions. To provide insights on the developed theory, some simulation examples are provided and discussed.