Cascade Optical Coherence Tomography (C-OCT) for Surface Form Metrology of - ProQuest

Freeform optical components enable dramatic advances in optical system performance and packaging. As the saying goes, “one cannot make what one cannot measure.” Surface form metrology of as-built freeform optics remains a challenge and an active area of research. In this dissertation, a novel cascade optical coherence tomography (C-OCT) technique was conceived towards addressing this metrology challenge. The C-OCT theoretical framework was developed, and a metrology system was built to demonstrate its working principle and metrology capability experimentally. Three significant areas were investigated to realize a C-OCT metrology system with nanometer-level measurement uncertainty. First, the sample arm requirements concerning telecentricity ...