Dual-beam holographic deflection measurement

Deflection is recorded at different sensilivities over a limited portion of the holographic range by introducing equal but opposite phase changes into the holograms created by a dual-beam illumination. The technique does not require a partially reflecting mirror, patterns can be optically filtered for better fringe contrast and in-plane displacement can be recorded without making any modifications in the experimental setup. Results obtained from two-and three-dimensional surfaces agree well with theory and verify analytical arguments presented throughout the paper.