Optical recording of stable holographic grating in a low TgTg statistical copolymer covalently functionalized with an azo-dye

•Diffraction gratings recorded in novel photoaddressable copolymer.•Highly stable recorded diffraction gratings.•Copolymer functionalization obtained by chemical modifications with 2-naphthol.

A novel photoaddressable copolymer with low glass transition temperature was synthesised and its optical properties were studied. The photoresponsive material was obtained from chemical modification of a poly(styrene-co-acrylic acid) copolymer. A holographic polarization grating was recorded in the material and was monitored by measuring its diffraction efficiency. It is shown that the holographic grating stored in the material is highly stable in time, despite the fact that the polymer glass transition temperature is near room temperature. This stability is a consequence of electrostatic interactions between the azo-groups and the carboxylic substituent group of the main polymer chain.