Characterisation and implementation of synthetic diamond as a Raman laser material
Diamond's unrivalled thermo-mechanical and optical properties make the material an attractive material for use in laser systems. Improvements in growth techniques over the past decade have led to a surge of research employing diamond in optical systems. This thesis presents the characterisation of diamond and its implementation in Raman lasers, utilising the materials high Raman gain as well as its impressive thermal properties. Diamond's potential as both an extremely compact and robust method for frequency conversion, allowing access to relevant but otherwise hard to reach wavelengths, and also as a means to convert low brightness sources to near diffraction limited beams will also be discussed. A pump-probe measurement is used to conduct the first systematic study of the Raman gain in diamond over a wide range of wavelengths, from 355nm to 1450nm, with a dependence observed. Using the high Raman gain measured, both CW and pulsed Raman systems were designed and characterised. An 11-fold brightness enhancement was achieved in an Nd:YAG pumped intra-cavity diamond Raman laser, while record powers of 7.6W are presented using an Yb:LuAG pumped diamond Raman laser. Two monolithic diamond Raman lasers are discussed, achieving near quantum limited conversion efficiencies. An investigation of the laser induced damage threshold of diamond surfaces is conducted, with attempts made to improve the measured value of 25Jcm-2 discussed.
Networked Digital Library of Theses and Dissertations