The interference of two plane waves with parallel polarization may be recorded in the photosensitive media as the phase and/or amplitude gratings, which is called the scalar hologram. It is not possible to record the hologram and reconstruct by the object using the recording beams having the mutually orthogonal polarizations. In this work, we have experimentally performed the reconstructions of scalar and vector holographic gratings recorded in amorphous $As_2S_3$ thin film and theoretically investigated the temporal behaviors of diffracted intensity of the gratings in terms of 3rd order nonlinear susceptibilities. Amorphous $As_2S_3$ thin films are deposited on slide glass by vacuum evaporation of bulk $As_2S_3$ in a vacuum of $10^{-6}$ Torr. Th typical thickness of the film is 3 m and linearly polarized Ar-ion laser beams (514.5nm) are used to record the photoinduced gratings in amorphous $As_2S_3$ thin film and an He-Ne laser (633nm) is used to read the hologram simultaneously. The behaviour of the photoinduced gratings recorded in $As_2S_3$ thin film are investigated mainly by measuring the 1st order diffraction efficiency as a function of exposure time. The observed time dependence of the diffracted signal is in good agreement with the temporal behaviors of theoretical results. From the experimental results we have estimated the 3rd order nonlinear susceptibilities, $x_{1111}^{(3)}=3.2\times10^{-2}$ esu and $X^{(3)}_{1122}/X^{(3)}_{1111}=0.98$ in the vicinity of the absorption edge of amorphous $As_2S_3$. These values are very much larger than the nonresonant transparent $X^{(3)}=10^{-13}esu$ at 1.06μm and comparable to the values of 1esu in InSb, and $5\times10^{-3}esu$ in GaAs. Further works on the improvement of the theory and the applications of vector holography to the optical image processing are needed.
