  We demonstrate the use of nanodiamond in constructing holographic
nanoparticle-polymer composite transmission gratings with large saturated
refractive index modulation amplitudes at both optical and slow-neutron
wavelengths, resulting in efficient control of light and slow-neutron beams.
Nanodiamond possesses a high refractive index at optical wavelengths and large
coherent and small incoherent scattering cross sections with low absorption at
slow-neutron wavelengths. We describe the synthesis of nanodiamond, the
preparation of photopolymerizable nanodiamond-polymer composite films, the
construction of transmission gratings in nanodiamond-polymer composite films
and light optical diffraction experiments. Results of slow-neutron diffraction
from such gratings are also presented.
