Primary aberrations alleviated with phase pupil filters

Conventional optical system design enhances the resolution of incoherent imaging systems by optical-only manipulations or some type of post-processing of an image that has been already formed. This paper gives a brief introduction to a modern method, which employs an aspherical phase filter to alter the transmitted wavefront in such a way that the optical system has a high tolerance to aberrations. As reported in earlier work, this approach alleviates the defocus and its related aberrations whilst maintaining the diffraction-limited resolution for incoherent imaging systems. We propose to explore the control of primary aberration through the use of radially symmetric phase filters and this include spherical aberration, coma, astigmatism, and Petzval field curvature aberration. This method offers the potential to implement diffraction-limited imaging systems using simple and low-cost one- or two-element lenses.