Abstract
Absolute physical thickness across the sample aperture is critical in determining the index of a refraction profile from the optical path length profile for gradient index (GRIN) materials, which have a designed inhomogeneous refractive index. Motivated by this application, instrumentation was established to measure the absolute thickness of samples with nominally plane-parallel surfaces up to 50 mm thick. The current system is capable of measuring absolute thickness with 120 nm () repeatability and submicrometer expanded measurement uncertainty. Beside GRIN materials, this method is also capable of measuring other inhomogeneous and opaque materials.
© 2015 Optical Society of America
Full Article | PDF ArticleMore Like This
R. Montonen, I. Kassamakov, E. Hæggström, and K. Österberg
Appl. Opt. 54(15) 4635-4639 (2015)
Yangjin Kim, Kenichi Hibino, Naohiko Sugita, and Mamoru Mitsuishi
Opt. Express 23(4) 4065-4073 (2015)
Jianing Yao, Jinxin Huang, Panomsak Meemon, Michael Ponting, and Jannick P. Rolland
Opt. Express 23(23) 30149-30164 (2015)