The Importance of Reference Fiducials in Freeform Design, Manufacturing, and Metrology

Timothy Lynch, MS Defense

Hopeman 224

Optical metrology is a key component of the optical manufacturing process. Regardless of how refined a fabrication process may be, it is incomplete without an accompanying metrology process by which to validate the results. For this reason, optical manufacturing and metrology must progress hand in hand in order to successfully advance the current state of the art.

With the introduction of freeforms and other geometrically complex optical components, the industry is in need of more comprehensive metrology solutions. In particular, traditional methods for locating optical surfaces with respect to mechanical features do not scale to freeform components. The solution to this dilemma is the integration of fiducials into the optical component. These reference datums link the optical surfaces of the component by establishing a constant coordinate system. This coordinate system can be referenced throughout manufacturing, metrology, and assembly to ensure proper alignment in all cases.

This research examines the implications of utilizing reference fiducials in the context of freeform optics. It will address the advantages over traditional alignment methods, as well as potential complications to consider.