Comparison of Geometrical and Diffraction Optical Transfer Functions

摘要

The geometrical and diffraction point-spread functions of an optical imaging system have been reviewed and compared in the past [V. N. Mahajan, "Comparison of geometrical and diffraction point-spread functions," SPIE Proc. 3729, 434-445 (1999)]. In this paper, we review and compare its corresponding optical transfer functions. While the truth lies with the diffraction OTF, it is considered easier and quicker to calculate the geometrical OTF, especially for large aberrations. We briefly describe the theory of the two OTFs, and explore the range of spatial frequencies and the magnitude of the primary aberrations over which the geometrical OTF may provide a reasonable approximation of the diffraction OTF.