Abstract
The most critical property of an imaging system is the degree of accuracy with which objects under surveillance can be imaged or reproduced by that system. This property is usually termed resolution, and is affected by both fundamental physical limits as well as environmental effects and manufacturing imperfections. This contribution presents the theoretical principles to quantify the imaging resolution limits of canonical passive and active imaging systems. The intrinsic resolution limit of basic imaging systems is computed based on the Rayleigh criterion and bandlimitation considerations in Fourier domain. The concept of superresolution is introduced, and the role of evanescent waves in enabling superresolution is discussed. The nonlinear nature of multiple scattering imaging is explained, and the possibility of achieving superresolution thanks to multiple scattering is discussed.