Second generation kinetically-enhanced copper vapour lasers: Recent advances

The performance of 100W small-scale "second-generation" kinetically-enhanced copper vapour lasers of active length 1 m long and volume 0.25-0.8L are reviewed. These systems have substantially reduced plasma tube insulation so that the lasers operate in a regime of high heat flux. The specific output powers are a factor of 2 higher than "first- generation" kinetically-enhanced copper vapour lasers and five-fold higher than copper vapour lasers operating without HCl additive. It is shown that the spatio-temporal gain characteristics remain well suited to efficient extraction of high beam quality output, as an amplifier or oscillator using unstable resonators. Radially-resolved measurements of the Cu density indicate that the plasma properties are much closer to equilibrium than expected from thermal models, indicating promise for further increases in specific output power. The implications for specific output power of H₂:CuBr and Cu HyBrID lasers are also considered.