Light propagation through photoinduced chiral structures in azobenzene-containing polymers

We investigate light propagation through azobenzene-containing polymers wit h photoinduced chiral structures. The structures have large pitch but the M auguin condition is not fulfilled. The eigenmodes are shown to be elliptica l and their ellipticity is determined by the ellipticity e(o) of the exciti ng light. In amorphous azopolymers, light induces a macroscopic chiral stru cture comprising the whole illuminated region. The pitch depends on the val ue of e(o): no chirality is induced if e(o) = 1 (circular polarization). In liquid-crystalline azopolymers circularly polarized light induces the form ation of many microscopic spirals, which makes the material equivalent to t he classical optically active media.