Demonstration of femtosecond laser induced refractive index change in silk-fibroin hydrogels.

We present induced refractive index changes in biocompatible silk fibroin hydrogels using two different femtosecond laser systems: one using 400 nm at 80 MHz and the other employing 517 nm at 8.3 MHz. Both modalities produced significant index changes, demonstrating the potential to create custom refractive correctors.