Formation of diffraction gratings in optically patternable hydrogel films
SabelāGrau, Tina; Zhang, Zhenfang; Rahman, Rahima; Lensen, Marga C.
Local 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.
