Vol. 47, Issue 4, pp. 579-590

Abstract

Heterodyne holographic interferometry is a well-known interferometric technique for high precision measurements of the phase difference between two recorded wave fronts. These wave fronts are typically registered at a given distance from the object under inspection. Although the affinity of heterodyne techniques with the phase-shifting ones is immediate, reports on concrete implemented set-ups from the former type of techniques as adaptations into the second type seems to be not so widely spread as convenient. To illustrate this point, in this communication we demonstrate two phase-shifting methods as applied to heterodyne holograms, each variant using a different shifting method for phase shifting. One method is based on a conventional piezoelectric stack transducer and the other method comprises modulation of polarization. The alternatives that these two techniques offer could be of direct benefit in dynamic holography.