Diffraction of quasimonochromatic partially space-coherent light by annular apertures, which are of fundamental importance when reflecting components are used, has been examined theoretically. The work on slit and circular apertures by previous workers has been briefly reviewed. Use has been made of Schell’s theorem which gives the relationship between the far-field intensity and the Fourier transform of the product of the source autocorrelation function and the correlation function across the diffracting aperture. Exponential, besinc, and sinc forms of the degree of coherence have been assumed and the results are presented for three typical values of the central obstruction of the circular aperture.
K. SINGH and H. S. DHILLON, "Diffraction of Partially Coherent Light by an Aberration-Free Annular Aperture," J. Opt. Soc. Am. 59, 395-398 (1969)