Patent ID: 11774236

Abstract:
A metrology frame configured to receive and secure a workpiece in preparation for an interferometric determination of a spatial profile of the workpiece with the use of one or more retroreflectors removably cooperated with the frame in known pre-determined spatial relationship with respect the fiducial features of not only the workpiece but those of the metrology frame itself. The metrology frame is necessarily devoid of a holographic optical element, while the measurement apparatus containing such metrology frame employs a hologram configured to generate at least one alignment optical wavefront that spatially converges on the retroreflector. The hologram is preferably structured as a set of constituent holographic regions (contained in the same, unitary or spatially-complementary housing and/or substrate) that perform different but operationally-complementary functions to facilitate the alignment of the metrology frame with respect to the converging optical wavefront with or without the workpiece in the frame. The optical measurement system employing the metrology frame and the hologram. Methods of optical alignment with use of same.