We have derived an expression for the combined effects of a converging beam of light and mirror misalignment on the interferograms obtained with a Michelson interferometer. Each effect has been considered separately by others and leads to symmetric interferograms whose modulation is less than 100%. The combined effect produces an asymmetry in the interferogram as well as a decrease in the modulation. The magnitude of the asymmetric term is given in terms of the optical parameters of the interferometer.
Louis W. Kunz and David Goorvitch, "Combined Effects of a Converging Beam of Light and Mirror Misalignment in Michelson Interferometry," Appl. Opt. 13, 1077-1079 (1974)