Analysis of second and third diffracted orders in volume diffraction gratings recorded on photopolymers

Abstract

In this paper the importance of the second and the third diffraction orders in volume holographic gratings recorded on photopolymers is analyzed. The existence of higher harmonics in the refractive index is also evaluated using the Rigorous Coupled Wave Theory (RCW) to fit the curves and to obtain quantitative information of these higher harmonics. Two different types of gratings are analyzed, on the first hand gratings with 35 µm of thickness and 1125 lines/mm are studied and on the second gratings with 70 µm of thickness and 545 lines/mm. Finally, the results obtained for the efficiency of the first diffraction order using Kogelnik's Theory are compared with those obtained using the RCW.