Specific output power scaling of kinetically-enhanced copper vapour lasers

We have investigated the power scaling behaviour of a kinetically enhanced copper vapour laser as a function of the plasma tube thermal insulation. By reducing the insulation to levels much lower than typically used for conventional copper vapour lasers we obtained increases in the specific output power of a small-to-medium scale device (0.8L) up to 130W/litre (ie., total output power 104W). The laser wall-plug efficiency remains approximately constant (∼1.4%) when the supplied power is increased from 5.9kW to 7.4kW. Radially-resolved Cu density measurements show that the depletion of Cu atoms is similar to other devices having much lower specific input power. The results show that kinetic enhancement reduces the depletion of atoms from the axial region by ion-pumping due to reduced fractional ionisation and rapid charge recombination during the interpulse period.