Abstract

Eight years ago we reported for the first time on neutron diffraction from holographic gratings written in light-sensitised poly(methyl methacrylate) [1] Since then, several improvements have been achieved: Replacement of a methyl group by nitrogen in poly(cyano acrylate) increases the coherent scattering amplitude by a factor of approximately 2.5 without significant deterioration of the amplitude of the light-optical holographic grating. Incoherent neutron scattering is further reduced by perdeuteration and the effect of the low lateral coherence of the neutron beams could be accounted for. By now holographic gratings with neutron diffraction efficiencies of more than 70 % for neutron wavelengths of about 4 nm can be produced. By exploiting the inherent nonlinearity of the kinetics of the photopolymerization process gratings with spatial frequencies of nearly 10,000 lines/mm have been achieved recently [2].

© 1998 IEEE