Abstract: An apparatus for the absolute measurement of a two dimensional optical path distribution comprising: a light source (4) for illuminating an object (26) with light having a plurality of wavelengths: an interferometer (12) for forming an image of at least part of the object, which image comprises a broad band interferogram; a hyperspectral imager (30) in optical communication with the interferometer for spectrally separating the broad band interferogram into a plurality of narrow band two dimensional interferograms (72, 74, 76); a register (38) for spatially registering the narrow band interferograms; an extractor for extracting one dimensional intensity signals from corresponding pixels in each narrow band interferogram; and a calculator (100) for calculating the frequency for each point on the object from a one dimensional intensity signal associated with that point.

Abstract: An apparatus for the absolute measurement of a two dimensional optical path distribution comprising: a light source (4) for illuminating an object (26) with light having a plurality of wavelengths: an interferometer (12) for forming an image of at least part of the object, which image comprises a broad band interferogram; a hyperspectral imager (30) in optical communication with the interferometer for spectrally separating the broad band interferogram into a plurality of narrow band two dimensional interferograms (72, 74, 76); a register (38) for spatially registering the narrow band interferograms; an extractor for extracting one dimensional intensity signals from corresponding pixels in each narrow band interferogram; and a calculator (100) for calculating the frequency for each point on the object from a one dimensional intensity signal associated with that point.