Patent ID: 7307706

Claim:
A method of estimating one or more optical characteristics of a Device-Under-Test (DUT), including the steps of: directing an optical wavefront, generated by a source, towards a test location; generating at least one ray from the wavefront at the test location; for each ray: at two or more measurement planes, each measurement plane transverse to the direction of travel of the wavefront and beyond the test location relative to the source and at different optical path distances, measuring respective points of intersection of the ray with the measurement planes with and without the DUT at the test location; determining the transverse aberration due to the DUT for the ray at each measurement plane; and, for each measurement plane estimating from the determined transverse aberrations the coefficients of a general transverse aberration equation, the coefficients of which are the product of a combination of optical characteristics and the optical distance between the measurement plane and the appropriate principal plane of the DUT; calculating the one or more optical characteristics from the estimates of the coefficients for each measurement plane and the optical distances between respective measurement planes; and one of the steps selected from the group consisting of: plotting the calculated optical characteristics as a map, aligning the DUT and an incident optical wavefront, and adjusting one of the optical characteristics of the DUT.