Coherent imaging by using defocus grating

We propose and demonstrate an coherent imaging technique by using defocus grating. For the imaging system, the defocus grating combined with lens with short focal length is used to realize multiplane imaging on the lens' focal plane, simultaneously. Based on these multiplane images, Gerchberg-Saxton (GS) algorithm is used to reconstruct the complex amplitude distribution of the input imaging beam. By using computational imaging and digital wavefront distortion correction with stochastic parallel gradient descent (SPGD) algorithm, this technology can be used for joint estimation of both pupil aberrations and an high resolution image of the object, successfully.