Basics of Interferometry - P. Hariharan - Google Books

https://books.google.de/books?id=sWbGSSQ6fPYC&pg=PA67#v=onepage

Optical interferometry is used in communications, medical imaging, astonomy, and structural measurement. With the use of an interferometer engineers and scientists are able to complete surface inspections of micromachined surfaces and semiconductors.…