A high-repetition rate (50 kHz) high power (10 W) gold vapour laser

We report the results from a new generation of gold vapour laser (GVL) that has been constructed with modern laser tube materials (that enable operation at temperatures up to 2000 °C) and a high pulse repetition rate power supply design (thyratron switched utilising two stages of magnetic pulse compression). Using a 22 mm bore by 61 cm long active volume and a plane-plane optical cavity the laser produced a 10 W transient of 627.8 nm output power from 4.3 kW of input power giving the laser an efficiency of 0.23% and a specific average output power (SAOP) of 0.043 Wcm^-3. These results represent the highest efficiency gold vapour laser published to date. Steady state operation of the laser using a polarized on-axis unstable cavity with magnification 40 produced 5.2 W of high beam quality light that was frequency doubled to produce 320 mW of 313.9 nm output. This laser source is suited to fibre Bragg grating (FBG) writing in germanium doped optical fibres, high speed imaging applications, simultaneous UV and red via hole drilling in Kapton and copper flexi-PCBs and deep UV generation (producing 209 nm output using third harmonic or sum-frequency mixing with the fundamental 312.2 nm laser line).