The influence of hydrogen on the output of A N2-CO2 laser

Pulsed inductive CO2 laser with radio-frequency excitation and influence of the H2 content on the efficiency and lasing temporal characteristics

“…In the experimental studies of helium-free gas mixtures N 2 :CO 2 = 3:1 and N 2 :CO 2 :H 2 = 3:1:[X] (X-hydrogen molecules, the partial content of which varied in the range of 0.5%-2% (pressure p ∼ 2 mbar)), increasing the H 2 from 0% to 2% led to a decrease in the maximum value of the inductive CO 2 laser output energy by approximately 1.3 times (from 380 to 280 mJ) during the study in the range of τ values from 2.5 to 20 ms. Further H 2 increase in our experimental studies of helium-free gas mixtures was considered inappropriate. However, it is well known (see [30][31][32][33]) that hydrogen presence in a gas mixture upon excitation by transverse (TEA discharge) and longitudinal electric discharges increases the amplification of an active medium due to the rise in the relaxation rate of the CO 2 molecule lower laser level. The following feature found in the experiment should be noted: when hydrogen-containing gas mixtures are RF-excited, as the τ value increased, the t puls values (FWHM) in the entire range of τ (from 2.5 to 20 ms) were recorded at the 1.8 ms level, while the t puls (baseline) values changed from 2.0 to 2.7 ms.…”

“…Further increasing the H 2 content leads to the CO 2 laser output power decreasing due to a noticeable quenching of the laser upper level. Also, it is well known [30][31][32][33] that the presence of H 2 in the gas mixture upon excitation by transverse transversely excited atmospheric (TEA discharge) and longitudinal electric discharges increases the discharge stability, increases the amplification of an active medium due to the increase in the relaxation rate of the CO 2 molecule lower laser level (the relaxation rate of the lower laser level with the participation of H 2 is 20 times higher than the relaxation rate with the participation of He), and leads to the deactivation of the laser upper level, which at high concentrations of H 2 reduces the gain and laser energy. In an inductive electrodeless discharge, no such studies have been carried out in CO 2 laser active medium.…”

Thermal Laser Excitation by Supersonic Mixing in a Gas Dynamic Nozzle

“…Although Howe [30] had observed that H2 added to pure CO 2 had no marked effect, Rosenberger [33] obtained improved performance with a N2-CO2-H2 system over a N2-CO2 system.…”