Generation of 13.9 µm radiation from CO₂ by cascade lasing or externally applied CO₂ laser

Abstract

13.9 µm radiation from the 10⁰0-01¹0 transition can be obtained from a CO₂ laser by saturating the 00⁰1-10⁰0, 10.6 µm transition with an internally generated q-switched pulse or by the application of an external 10.6 µm pulse. Because of Fermi resonance between the symmetric stretch and the bending modes, decay of population from the 10⁰0 level is fast, and such lasers operate at low power and energies. A theoretical model was developed to study such lasers. The results of the calculations indicate that a large-aperture E-beam-sustained discharge is effective for excitation of the cryogenically cooled gain medium, which uses He rich mixture at low pressure. The system is scalable and capable of generating large powers and energies.