公开(公告)号：US09857169B1

公开(公告)日：2018-01-02

申请号：US15385143

申请日：2016-12-20

Applicant: 4D TECHNOLOGY CORPORATION

Inventor： Michael North Morris ,  James Millerd

IPC: G01B11/24 ,  G01B11/255 ,  G01B9/02

CPC classification number: G01B11/255 ,  G01B9/02065 ,  G01B9/02081 ,  G01B9/0209 ,  G01B2290/15 ,  G01B2290/70 ,  G01M11/005

Abstract: An interferometer includes a short-coherence source and an internal path-matching assembly contained within its housing. Because path matching occurs within the housing of the interferometer, it is removed from external environmental factors that affect measurements. Therefore, a single cateye measurement of an exemplary surface can be performed in advance and stored as a calibration for subsequent radius-of-curvature measurements. In one embodiment, a path-matching stage is incorporated into a dynamic interferometer where orthogonally polarized test and reference beams are fed to a dynamic imaging system. In another embodiment, orthogonal linearly polarized test and reference beams are injected into a remote dynamic interferometer by means of one single-mode polarization-maintaining optical fiber.