Efficient laser emission via a diode-pumped arc-plasma-state gain medium

The diode-pumped metastable rare gas laser (DPRGL) is a promising approach for high-energy laser generation, yet achieving high-efficiency operation requires producing high column densities of metastable atoms (>10 14 cm −2 ). Traditional atmospheric-pressure plasmas struggle to simultaneously attain both high time-averaged metastable densities and extended gain lengths. In this work, we proposed and demonstrated an efficient laser emission scheme using a diode-pumped arc plasma, generating a 2-cm-long gain medium with an Ar metastable density exceeding 1×10 14 cm −3 above atmospheric pressure. This configuration enables validation of its operational mechanism under conditions of sufficient column density. The system delivered an average output power of 14.4 W with a slope efficiency of 36%, offering a viable pathway toward higher-power DPRGL systems. Power scaling could be further improved by increasing pump intensity and volumetrically expanding the plasma through multi-arc discharge arrays.