Patent Document ID: 20080285053
Application ID: 12039185
Patent Flag: 0

Claim One:
1. A method for obtaining at least one of the shape, thickness variation, and inhomogeneity of objects having a plurality of surfaces comprising: initiating an unequal path interferometer assembly comprising: a first reference flat having a first length L 1 in a first dimension; a second reference flat having a second length L 2 in the first dimension; a cavity D 1 defined by a distance between the first reference flat and the second reference flat; and a receptacle to receive an object in the cavity such that an optical path remains open between the first reference flat and the second reference flat; receiving a coherent tunable light source to the unequal path interferometer assembly; recording multiple optical interferograms in response to known phase shifts produced by changes in the wavelength of light from the tunable source; extracting phases of each of the interferograms to produce multiple phase maps; and determining each map from its corresponding interferogram using a weighted least-square algorithm.