Application of a cubic phase plate to a reflecting telescope for extension of depth of field

Abstract

Wavefront coding is an accepted technique to extend the depth of field in incoherent optical systems. We present the design of a reflecting telescope with wavefront coding by employing a cubic phase plate (CPP). We propose a method to reduce the CPP size by changing its position from the aperture stop to a secondary mirror without varying the point-spread function, which is insensitive to defocusing. This change in position reduces the diameter by almost three orders and increases the third-order coefficients of the x y polynomial surface by two orders, thus easing manufacturing.

Point spread function engineering based on wavefront phase modulation

“…In addition, as a small aberration system, the microscope can be modeled as a diffraction-limited system, which is very suitable for wavefront coding modification. In addition to microscopes, wavefront coding can also be used to extend the DOF of optical endoscopes 82 , iris imaging systems 111,123,124 , telescopes 125 , and photographic systems 48,83,84,117 .…”