Femtosecond writing of refractive-index changes in sapphire is demonstrated by doping the crystal with an appropriate ion (here: Ti3+) that reduces the threshold of the process. Passive and active buried channel waveguiding is demonstrated.
László Forró, Endre Horvath, Bálint Náfrádi, Konrad Domanski, Márton Kollár, Pavao Roko Andricevic