Patent ID: 8743373

Claim:
An interferometry system for testing samples under test including those with high aberrations, comprising: a source of a test wavefront, whereby an axial line is defined by a direction of propagation of the test wavefront from said source; a tilt mirror tiltable with at least one degree of freedom about at least one tilt mirror axis and translatable along said axial line, situated in a path of the test wavefront propagation from said source; a reference mirror situated in a path of propagation of the test wavefront after the test wavefront has been reflected by said tilt mirror; a computerized control system and mechanical apparatus responsive thereto for controlling an axial displacement between a sample under test and said reference mirror, with the sample under test situated between said tilt mirror and said reference mirror; said computerized control system and mechanical apparatus responsive thereto for further controlling a tilt mirror angle of said tilt mirror about said at least one tilt mirror axis and a translation of said tilt mirror along said axial line; and a computerized device including a processor for deriving a substantially complete first-tilt-alignment wavefront metrology of the sample under test from a plurality of first-tilt-alignment interferograms, wherein, responsive to said computerized control system: said plurality of first-tilt-alignment interferograms is obtained with said tilt mirror oriented at a first predetermined tilt mirror angle relative to said propagation of the test wavefront; and each of said first-tilt-alignment interferograms is obtained, with said first predetermined tilt mirror angle held fixed, by said mechanical apparatus discretely varying said displacement between the sample under test and said reference mirror.