Influence of thickness and polarization on diffraction efficiency of direct patterned diffraction gratings in carbazole-based azopolymer films

Abstract

In this paper we report on direct holographic recording of surface relief gratings in carbazole-based azopolymers. Azo dye Disperse Orange 3 was chemically bonded to oligomer poly-N-(epoxypropyl carbazole) making surface deformation efficient in the presence of optical field gradient. Optimal of the film thickness were determined. Holographic recording at different polarization configurations showed that the P:P polarization of recording beams provides the maximum of diffraction efficiency about 33%. Investigation of the obtained gratings revealed that this value of diffraction efficiency is caused by surface relief modulation (up to 440 nm) during holographic recording. Measured surface profile depth may be the evidence that the main contribution in the value of diffraction efficiency of recorded holographic grating brings the surface relief grating.