Diffraction by two volume holographic gratings in a parallel arrangement

In this work is analyzed theoretically and experimentally the diffraction originated by an optical system composed by two identical and parallel volume holographic gratings recorded in a photopolymerizable glass. This optical system exhibit a tolerance reduction for out of the Bragg resonance. This property is studied to increase the resolution of confocal holographic microscopes and spectral analyzers by substituting the diffractive elements of these systems by two identical and parallel diffraction gratings. © Sociedad Española de Óptica.