Patent ID: 9234741
Filing Date: 2016-01-12
CPC Classification: G01B,G01M

Claim Text:
1. A method for interferometric testing of a non-spherical surface (SUT), the method comprising: reflecting first and second beams of light, formed by a diffractive element from an input beam of light having an input beam wavefront and incident onto the diffractive element along an optical axis, from the SUT to form first and second reflected beams such that modifying a spatial distribution of reflectivity of the SUT to independently attenuate the first and second reflected beams; and determining, with the use of a control unit that includes data-processing circuitry, a non-spheric profile of the SUT based on optical data, said optical data derived from a distribution of irradiance that is interferometrically formed by said first and second reflected beams upon co-axial propagation thereof.