Optical Frequency Response Characteristics in the presence of Spherical Aberration measured by an automatically recording Interferometric Instrument

Abstract

An interferometric method is described which measures the frequency response characteristics of a lens, with automatic recording of the curves. The theory of the method is given, followed by a discussion of the problems arising in the design of the instrument. A new type of interferometer was devised, having very stable adjustment and permitting accurate control of the path length and relative lateral shear of the two interfering wave fronts. Using a double beam shearing interferometer, with corner cube reflectors, it was also possible to measure the spatial phase shift term of the complex frequency response and record this automatically.