Direct writing of photonic devices using femtosecond laser pulses

We report on our capabilities to fabricate photonic devices in a large variety of different transparent dielectrics including highly nonlinear and active glasses as well as crystalline materials using tightly focused femtosecond laser pulses. We contrast the inscription of optical waveguides via thermal diffusion and cumulative heating and also discuss the realisation of depressed-cladding structures as well as stress-field induced guides. The fabrication of devices ranging from low loss optical waveguides, splitters, interferometers and resonant structures like waveguide Bragg gratings to more complex elements like integrated lasers and quantum circuits is demonstrated.