Measurement of optical transfer functions making use of a wavefront-shearing interferometer usually requires the path difference between the two arms of the interferometer to be varied.
The same effect can be achieved by a polarizing technique and, depending on the polarizing arrangement, either the modulus, or the real and imaginary parts of the optical transfer function can be recorded.
The theory of these two methods is given and the experimental procedure is described. Transfer functions for a defocused optical system are measured and are in good agreement with calculated results. Some of the problems involved in the measurement of the argument of the transfer function with an interferometer are also briefly discussed.
ANTHONY J. MONTGOMERY, "Two Methods of Measuring Optical Transfer Functions with an Interferometer," J. Opt. Soc. Am. 56, 624-628 (1966)