Photoinduced Holographic Gratings in Azobenzene-Functionalized Poly(amideimide)s

Abstract

We present the diffraction grating recording in a series of poly(amideimide)s functionalized with methyl-substituted azobenzene chromophore as side group and correlate the results with the molecular structure. Poly(amideimide)s, differing in their backbone structure and in position in which azobenzene group is attached to polymer chain, were synthesized and characterized by the spectroscopic methods. Diffraction gratings were fabricated using degenerate two-wave mixing technique with cw Ar+ laser working at λ=514.5 nm and monitored by light diffraction of low power He-Ne probe beam λ=632.8 nm in a transmission mode. Two qualitatively different configurations of the recording beam polarizations were used s-s and s-p. The dynamics of diffraction grating inscription was described by mono- or biexponential growth functions. The surface relief grating formation was also examined in poly(amideimide)s. They were studied by atomic force microscope and revealed the strong dependence on the writing beams polarization. Additionally the thermal stability of the photoinduced surface gratings was checked.