Fig. 1.

Numerical algorithms used for reconstruction of digitally recorded holograms: (a) multiplication of complex amplitude of hologram, $h(k,l)$, with 2-D complex chirp function, $\psi (k,l)$, (b) numerical reconstruction of the hologram, $\mathrm{\Gamma }(m,n)$, by 2-D FFT, (c) typical examples of modulation and wrapped optical phase of a reconstructed double-exposure (DE) hologram corresponding to sound-induced displacements of a TM sample, and (d) unwrapping the optical phase difference to obtain the fringe locus function, $\mathrm{\Omega }(m,n)$.