Average-power scaling of self-heated Sr⁺ afterglow recombination lasers

The performance of a large-bore (25 mm) self-heated Sr+ (430.5 nm) recombination laser with longitudinal excitation is discussed in relation to the prospects for scaling average output power to the 5-10 W regime. Average-power scaling is found to be limited in large-bore laser tubes by slow interpulse thermal relaxation in the laser gas mixture with strong radial gradients in species’ densities and temperatures at only modest pulse repetition frequencies, leading to premature termination of the population inversion on the tube axis. Proposals are discussed for circumventing these limitations in order to permit generation of multiwatt average laser output power at 430.5 nm from Sr+.