Electrically Switchable Gratings Formed Using Ultrafast Holographic Two-Photon-Induced Photopolymerization

Periodic gratings were formed using ultrafast holography to initiate two-photon-induced photopolymerization of a reactive monomer mixed with liquid crystal. The resulting structure shown in the cross-sectional SEM micrograph (scale bar = 3 μm) consists of periodic lamellae of polymer-dispersed liquid crystals and dense polymer. This periodic structure generates a refractive index modulation that gave rise to diffraction of light. The far-field diffraction intensity pattern can be modulated by applying an electric field across the holographic grating.