Phase shifting interferometer for the characterization of nanodevices

A new phase shifting interferometry based on the integrating-bucket technique with sinusoidal phase modulation is presented. The phase modulation is achieved by sinusoidal oscillation of an objective and a mirror attached to a PZT. Phase images are produced in real time at a rate of several Hertz. The system is not very sensitive to the vibrations and gives excellent accuracies and repeatabilities which makes it very suitable to the characterization of the nanodevices.