Research on the effect of phase mask to extend the depth of field of optical system

Abstract

The technique of wavefront coding can extend the depth of field of incoherent optical systems in which the design of phase mask is very important. Several designs of phase mask are proposed in this paper, the MTFs(magnitude of optical transfer function) of these methods are deduced and the figures of MTFs are compared and discussed. The simulation results are presented that MTFs are insensitive to misfocus and never to be zero which would occur in traditional incoherent optical systems. Based on subjective evaluation and quantitative simulation results, we believe that special designof phase masks is effective to expand the depth of an incoherent optical system.