Sarah Louise Geoghegan

Development of high quality single crystal diamond for novel laser applications

The extreme properties of diamond make it an exceptional material for a range of demanding optical applications. However, the use of single crystal diamond in lasers has been limited by the availability of suitably-sized crystals with low absorption, and the relatively high levels of strain-related birefringence present. We present recent progress in CVD diamond synthesis which addresses these properties, and show how this new high quality, engineered diamond is enabling novel laser technologies such as mid-IR semiconductor disk lasers and high efficiency diamond Raman lasers.

1.6 W continuous-wave Raman laser using low-loss synthetic diamond.

Low-birefringence (Δn<2x10(-6)), low-loss (absorption coefficient <0.006 cm(-1) at 1064 nm), single-crystal, synthetic diamond has been exploited in a CW Raman laser. The diamond Raman laser was intracavity pumped within a Nd:YVO4 laser. At the Raman laser wavelength of 1240 nm, CW output powers of 1.6 W and a slope efficiency with respect to the absorbed diode-laser pump power (at 808 nm) of ~18% were measured. In quasi-CW operation, maximum on-time output powers of 2.8 W (slope efficiency ~24%) were observed, resulting in an absorbed diode-laser pump power to the Raman laser output power conversion efficiency of 13%.