The results of experiments involving the storage of hologram in evaporated thin film of $As_2S_3$ (arsenic trisulfide) and $LiNbO_3$ (Lithium Niobate) are presented. Gratings have been formed in the recording materials by direct exposure without subsequent processing. Optically induced refractive index changes have been observed with laser exposure. A simple relationship between diffraction efficiency and exposure time is discussed.