High-power continuously tunable atmospheric-pressure CO$_2$ laser operating in the superregenerative amplification regime

The phenomenon of regenerative amplification was used as the basis of a high-power ($\sim50$ MW) continuously tunable atmospheric-pressure CO$_2$ laser with ultraviolet preionization. Lasing was observed in an optical system in which a high-pressure CO$_2$ laser was used as a master oscillator. When an energy of the order of 500 $\mu$ J was injected into a nonselective confocal unstable resonator of a regenerative amplifier, the continuous tuning range reached $\sim$(4–5)$\times10^{-2}$ cm$^{-1}$ for each of the several lines in the $P$ and $R$ branches and the width of the emitted line was $\delta\nu_{\text{las}}\lesssim$(4–5)$\times10^{-3}$ cm$^{-1}$.