We report results of dichroism and birefringence measurements on Dispe
rse Red 1 (DR1) in hybrid polymers. To investigate the influence of th
e matrix-chromophore interaction, we employ doped and functionalized s
ystems using three kinds of matrices with different rigidity. Writing,
erasing, and rewriting processes are performed on the polymer films a
t temperatures ranging from 50 to 300 K. Two processes are recognized,
the photochemical cis-trans isomerization of the dye molecules and a
thermal motion of the photoactive chromophore inside the surrounding m
atrix. By comparing results obtained from the different network system
s, we find that the main parameter correlated with the extent of induc
ed anisotropy is the degree of mobility of the chromophore within the
surrounding matrix.