A noncontacting surface profiling technique with 1-nm height resolution is described. A feedback arrangement keeps in quadrature the two arms of a confocal interference microscope by modulating the reference beam using an electrooptic phase modulator.
© 1986 Optical Society of America
Original Manuscript: January 28, 1986
Published: July 15, 1986
Hubert J. Matthews, Douglas K. Hamilton, and Colin J. R. Sheppard, "Surface profiling by phase-locked interferometry," Appl. Opt. 25, 2372-2374 (1986)