Patent ID: 8625102

Claim:
An aberration measurement system comprising: an interferometer that includes a polarization adjuster configured to adjust a polarization plane of coherent light, and a phase shifter configured to shift a phase of reference light, the interferometer being configured to split the coherent light into the reference light and test light and to enable an interference pattern to be observed which is obtained by an interference between the reference light and the test light that has transmitted a test object; and a signal processing unit configured to obtain a nonpolarization aberration of the test object, and coefficients a=sin ε cos 2θ, b=sin ε sin 2θ, and c=cos ε for a retardation amount 2ε and a principal axis direction θ of a polarization aberration of the test object, based on data of a plurality of interference pattern images which provide at least three complex visibilities obtained from the interferometer after the polarization adjuster adjusts the polarization plane of the coherent light, and to determine signs of the coefficients a, b, and c based on the nonpolarization aberration.