1. A study of the combined effects of aberration & a central obstruction of the pupil on the contrast objectives using mirrors;Rteel,1953
2. Transfer Function of an Annular Aperture in the Presence of Spherical Aberration
3. Use of Annular Apertures to Increase Focal Depth
4. Characteristics of Optical Transfer Function of Double Annular Aperture;Hong,1980
5. Evaluation of MTF for Fractal Optical Modulator of Semiconductor;Jebbar,2007