Biopolymer holographic diffraction gratings

Abstract

Surface-relief diffraction gratings are holographically recorded in dextran sensitized with ammonium dichromate (DCD). DCD was exposed with single-frequency 200mW diode pumped ND-YAG laser, at 532nm. The diffraction grating profiles were analyzed by atomic force microscopy (AFM). It was found that different surface profiles could be obtained. Gratings with 330lines/mm spatial frequencies were made. Existence of higher harmonics in Fourier Transform of non-sinusoidal profiles shows that DCD is capable of recording spatial frequencies up to 1320lines/mm (four times fundamental frequency). The measured maximum relief depth of the DCD grating is 402nm.