B. Ovryn et Jh. Andrews, Measurement of changes in optical path length and reflectivity with phase-shifting laser feedback interferometry, APPL OPTICS, 38(10), 1999, pp. 1959-1967
The operating characteristics of a novel phase-shifting interferometer are
presented. Interference arises by reflecting the light from a sample back i
nto the cavity of a cw He-Ne laser. Changes in phase and fringe visibility
are calculated from an overdetermined set of phase-shifted intensity measur
ements with the phase shifts being introduced with an electro-optic modulat
or. The interferometer is sensitive enough to measure displacements below 1
Hz with a rms error of approximately 1 nm from a sample that reflects only
3% of the 28 mu W that is incident on its surface. The interferometer is a
pplied to the determination of cantilever bending of a piezoelectric bimorp
h. (C) 1999 Optical Society of America.