Investigation of a high-pressure continuously tunable CO₂laser

Abstract

An experimental and theoretical investigation was made of the frequency tuning of a pulse electron-beamcontrolled CO2 laser. A continuous tuning was achieved in a range of ~45 cm–1 and the energy per pulse was ~0.1 J when the pressure in the laser mixture was 5 atm. The frequency pulling of the multimodestructure envelope of the gain lines was observed. This pulling was practically eliminated by inserting in the resonator a lens telescope or a prism, which increased the diameter of the beam on a diffraction grating. The spectral width of the radiation was ~0.05 –1. The results of a theoretical calculation of the tuning characteristics of the laser were close to the experimental data. A continuously tunable CO2 laser was used in resonant excitation of visible luminescence in ethylene and optoacoustic detection of deuterated molecules HDS and NH2D in natural isotopic mixtures of hydrogen sulfide and ammonia.