THERMAL LASER EXCITATION BY MIXING IN A HIGHLY CONVECTIVE FLOW

Abstract

Population inversion has been generated through the mixing of CO2 or N2O into a supersonic N2 flow, vibrationally excited by thermal means. Gain at 10.6μ, corresponding to the 001 → 100 transition in CO2, equal to 0.8%/cm has been measured in this medium. Using an optical cavity, oriented transverse to the flow, up to 60-W cw laser power at 10.6μ from CO2 was extracted from a 5-cm length by 1.2-cm2 cross-section active volume. When N2O was substituted for CO2 in the mixing region, cw laser emission was demonstrated at 10.8μ, corresponding to the 001 → 100 transition in N2O.