Recent developments in bulk waveguide devices fabricated at Macquarie University using ultrafast laser direct-write techniques

In 1996, it was demonstrated that focussed infrared femtosecond laser pulses can induce a local internal increase in the refractive index of bulk transparent glasses. This discovery offered unique opportunities for the fabrication of arbitrary 3D photonic waveguide devices inside a wide range of materials simply by translating a sample through the focal point of a focussed femtosecond laser beam. Not only can this direct-write technique be carried out rapidly, it is readily compatible with existing fibre systems, it does not require a lithographic mask and it can be conducted in a regular laboratory environment with the minimum of sample preparation. This presentation explores the contributions, carried out at the CUDOS at Macquarie University, to the field of femtosecond laser direct-written waveguide devices and an outlook into future investigations. In particular, studies into writing polarisation, directional couplers, waveguide Bragg gratings, waveguide amplifiers and waveguide laser oscillators will be presented.