Submicron confocal Raman imaging of holograms in multicomponent photopolymers

We report submicron chemical imaging of optical holograms in multicomponent photopolymers using a confocal scanning Raman microscope. The microscope is sensitive to the submicron, ∼1% concentration variations of the polymeric components that form refractive index modulations (Δn) responsible for hologram diffraction. Concentration variations are established by both small molecule diffusion and polymer matrix swelling during hologram writing. Both density and composition variations contribute to Δn. These measurements demonstrate that submicron Raman microscopy is applicable to multicomponent organic, inorganic, and hybrid materials as a route to correlate materials chemistry/morphology with their physical properties.