Off-axis aberration correction for a wide field scanning telescope

Abstract

Due to the tradeoff between field of view and resolution, the ability of traditional optical telescopes to obtain high-resolution wide field images is limited. This work presents a design for a scanning optical telescope that can produce high resolution images over a wide field of view. This is accomplished by scanning one of the telescope's optical elements. Inherent in such a design is the introduction of optical aberrations as off-axis scanning occurs. The deformable mirror technology is implemented to adaptively correct these aberrations such that on-axis resolution is achieved at off-axis scan angles. The optical design layout is optimized in software to minimize on-axis wavefront aberrations. This paper presents results involving two deformable mirrors based on different technologies: the AgilOptics mirror based on electrostatic actuators and the Imagine Optic mirror based on electromagnetic actuators. Both mirrors are similar in size (about 15mm aperture), but the Imagine Optic mirror has significantly larger actuator displacement, though at a higher cost. The static telescope design has a field of view of 0.49-degrees which is increased to 20-degrees with the AgilOptics mirror and 40-degrees with the Imagine Optic mirror.