Phase mask based interferometer: Operation principle, performance, and application to thermoelastic phenomena

A simple, versatile, sensitive optical interferometer based on diffractive optics is presented. The absence of a need for active stabilization, and a compact common-path design requiring two optical elements, make the interferometer ideal for time-resolved measurements in the picosecond through millisecond regimes. Its performance is characterized quantitatively, and its utility for local detection and scanning as well as spatially resolved imaging of thermoelastically induced strain is demonstrated.