Radio-frequency distributed-exciting waveguide CO2 laser with gain length of 14.0 m

Abstract

We have developed a waveguide CO₂ laser with distributed radio frequency (RF) excitation. The laser featured a folded seven-channel stable cavity structure. The physical length of laser propagation along the centerline of each channel was 2.1 m, and the total length of the gain region reached 14.0 m. Four synchronous RF exciting modules were adopted in order to realize uniform discharge in the length of 2.1 m. The output power of 405.9 W was achieved. The beam quality factors $M_x^2$ and $M_y^2$ were 1.43 and 1.58, respectively. To the best of our knowledge, 14.0 m is currently the longest single-pass gain length reported in folded waveguide structures. The laser provides a novel technical routine for achieving longer gain region, which is beneficial for amplifying CO₂ lasers.