Aberrated Point-Spread Functions and Beam Quality for Optical Systems with Annular Pupils
AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH
Pagination or Media Count:
The effect of the central obscuration of an annular pupil of an incoherent optical imaging system on its aberrated point-spread function PSF is discussed. A simple model is presented which approximates the aberrated PSF by an aberration-free PSF scaled by its Strehl ratio. The approximation of a PSF with rotationally symmetric aberration by an aberration-free PSF scaled by the Strehl ratio improves as the obscuration of the pupil increases. Specifically, as the obscuration approached the outer radius, the PSF of the optical systems with rotationally symmetric aberrations. For the rotationally nonsymmetric aberrations of astigmatism, balanced astigmatism, and coma the aberrated PSF in its central region can also be approximated by the scaled aberration-free PSF but for large Strehl ratios. For rotationally nonsymmetric aberrations, the region or spot sizes are given for which the aberration-free encircled energy without scaling by the Strehl ratio provides better agreement with the actual aberrated encircled energy than the aberration-free encircled energy scaled by the Strehl ratio.