Application of nanodiamond-polymer composite holographic gratings in a very cold neutron interferometer

In recent decades, photosensitive materials have been used for the development of optical devices not only for light, but also for cold and very cold neutrons. We show that holographically recorded gratings in nanodiamond-polymer composites (nDPC) form ideal diffraction elements for very cold neutrons. Their advantage of high diffraction efficiency, combined with low angular selectivity as a two-port beam splitter, meets the necessary conditions for application in a very cold neutron interferometer. We provide an overview of the latest achievements in the construction of such a triple Laue interferometer. A first operational test of the interferometer is planned immediately after this conference in May 2025.