Significant improvement of the thermal stability of the hologram recorded on photochromic materials had been achieved via covalent bonding of the photochromic dye to the polymer matrix as compared to the host-guest systems. For the photochromic materials with covalent bonding of the dye to the polymer matrix the level of thermal stability is demonstrated such that at temperatures (T) ca. 100 degrees C there was no detectable diffusion-type degradation of the hologram's diffraction efficiency after 6 h of exposure to elevated T. The same heating of the hologram in photochromic host-guest polymer led to a full hologram erasure within 40 min. (C) 2009 Optical Society of America