Features of double-spiral "valley-hills" surface topography formation in photochromic cholesteric oligomer-based films and their changes under polarized light action

Using a novel experimental method combining of polarizing optical microscopy (POM) and atomic force microscopy (AFM), the surface topography and optical properties of chiral‐ photochromic LC systems were studied. For this purpose, a mixture of cholesteric cyclosiloxanes with azobenzene‐containing dopant was prepared. Correlations between the features of surface topography of mixture films and POM images of planarly oriented texture were found. Polarized light action (532 nm) leads to the formation of partially aligned surface structure features. The observed photooptical effects are associated with E‐Z, Z‐E isomerization cycles of azobenzene groups, anisotropic cooperative photoinduced rotational diffusion and directional mass‐transport of chromophores and mesogens in the films.