A closed loop phase control system using an all-fiber optical configuration has been developed for use in phase stepping interferometry. This system drives the relative phase of two interfering beams through a sequence of π/2 rad increments so that the initial relative phase of these beams can be determined. This phase stepping system uses optical fibers to provide spatially uniform phase steps from a flexible, easily aligned optical configuration. In addition, this system uses phase feed back to eliminate phase modulator errors and to compensate for phase drifts caused by environmental disturbances.
© 1991 Optical Society of America
Original Manuscript: January 12, 1990
Published: March 1, 1991
Carolyn R. Mercer and Glenn Beheim, "Fiber optic phase stepping system for interferometry," Appl. Opt. 30, 729-734 (1991)