PUNCTUATED QUADRATURE PHASE-SHIFTING INTERFEROMETRY

We describe a method and algorithm for reducing the sensitivity of pha se-shifting interferometry to external vibrations. Using an interline- transfer camera, a shutter, and a fast phase shifter, we acquire a ser ies of paired interferograms in quadrature, with the pairs spaced to m aximize residual phase-error cancellation. The rapid acquisition of qu adrature pairs significantly improves resistance of interferometry to low-frequency vibrations. (C) 1998 Optical Society of America.