Formation of diffraction gratings in optically patternable hydrogel films

Abstract

AbstractLocal light‐induced material response forms the basis for volume holographic patterning of light‐responsive materials. This enables applications as multifunctional biomedical materials capable of integrating optical functions, such as for advanced intraocular lens (IOL) implants. Therefore, hydrogel films based on 8‐arm PEG and azobenzene‐functionalized acrylates are prepared. A local change in optical properties is induced by UV exposure: a decrease in refractive index is detected by ellipsometric examination. One‐dimensional diffractive surface gratings, generated using a photomask, show optical functionality and are visualized in the atomic force microscope. The results show that a local change in optical properties can be induced in functionalized hydrogel films by photochemical crosslinking, making them suitable for volume holographic patterning.