Abstract

A feedback control-equipped phase-shifting laser diode interferometer that eliminates external disturbance is proposed, the loop of which is stabilized by an adaptive control, with the CCD camera’s image-capture in time with the phase-shift, so that the sequence of the interference fringe is automatically determined, resulting in vastly simplified signal-processing. Several experiments confirm the repeatability of the measured value at 1.8 nm.

© 2006 Optical Society of America