Resolution-enhanced imaging by interferenceless coded aperture correlation holography with two competing methods of phase mask synthesis
Jawahar Prabhakar Desai, Joseph Rosen
Abstract
Introducing a scattering phase mask between an object and an objective lens can improve the imaging resolution of a maskless system. The resolution enhancement is achieved using the technique of interferenceless coded aperture correlation holography with a point spread hologram (PSH) of N randomly distributed dots. For the same PSH type, there is more than one way to synthesize the phase mask. In this study, we suggest a new method of synthesizing masks and compare it with the previous method. The new method is random multiplexing of linear phase functions, each of which is responsible for a single dot on the camera plane. The previous method is based on the well-known iterative Gerchberg-Saxton algorithm with the constraints of a randomly chosen dot pattern on the camera plane and a pure phase function on the mask plane. In terms of the signal-to-noise ratio of the reconstructed image, the iterative algorithm is better for high N but worse for low N, as expected. This article has also answered the question of which method is preferred to synthesize the phase mask.