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Enhanced photoinduced birefringence in hydrogen-bonded polymer-dye complexes

Photoinduced optical anisotropy of azobenzene-containing polymers has emerged as a source of exciting optical phenomena with a range of potential applications. Here we show that the benefits of the guest-host and covalently-linked systems can be combined by exploiting specific non-covalent interactions between the dye molecules and the polymer host. More precisely, hydrogen bonding between the dye and the polymer host enables to use high dye concentrations compared to conventional guest-host polymers and also improves the temporal stability of the anisotropic alignment of the dyes. We studied the photoinduced anisotropy of a common azo-dye, Disperse Red 1 (DR1), doped in polystyrene (PS) and poly(4-vinylphenol) (PVPh).