Ultralow-noise high-power DCN laser with rf pumping

An rf (27.5 MHz) discharge was used for the first time to pump a cw DCN laser, which made it possible to reduce its noise below the 10^–4 (0.01%) level. The parameters of the active medium and of the laser cavity were optimised. It was found that cw operation was possible at five wavelengths near 200 μm. A record output power from a laser with a cavity 2.5 m long, reached at the 189.95 μm wavelength, was 430 mW. In this laser the consumption of the expensive deuterated ethylene C₂D₄ was 20 times less than the consumption of the deuterated methane CD₄ in the most powerful dc-pumped DCN laser.