The temperature mode of development of the latent image of a holographic recording on a photothermoplastic medium when heated by unmodulated laser radiation is studied. The solution of the nonstationary heat conduction problem for multilayer structures made it possible to obtain an analytical expression for the temperature of the recording surface, depending on the thermophysical parameters of the carrier layers and on the power of the heating source. It is shown that, depending on the optical properties of the layers of the material and on the wavelength of the heating radiation, different modes of development of holograms on photothermoplastic carriers are realized.
A theoretical analysis of the hologram recording process on photothermal media to estimate the required laser radiation power for the information recording as the function of the spatial frequency and radiation exposure duration is considered. Results of the analysis showed that materials with a low thermal diffusivity are necessary to increase the recording density in these media and the recording should be performed with short pulses to minimize the thermal diffusion length. A solution for the heat conduction equation for photothermal materials heated by an interference laser field was found. The solution obtained allows one to determine the required value of the recording temperature for given spatial frequencies, depending on the thermal physical parameters of the medium and on the power and duration of the heating radiation.