Stimulated Brillouin scattering of CO2 radiation in compressed xenon

Stimulated Brillouin scattering (STBS) and phase conjugation of CO₂ laser radiation have been demonstrated experimentally for the first time in compressed xenon (59 atm at 21°C) located inside the low-Q cavity of this laser. The nonlinear medium was exposed to the action of counterpropagating focused multimode radiation beams. The difference between the frequencies of the longitudinal cavity modes was set at the frequency of the acoustic wave (v _s=32.2±0.3 MHz) excited as a result of STBS by 9.584 μm radiation. The duration of the radiation pulse τ _L was close to the acoustic phonon lifetime (τ _L<τ _ph≈3× 10⁻⁶s). The excitation of STBS was manifested experimentally as the locking of longitudinal modes, an increase in power and energy, and also an increase in the duration of the lasing pulse and a reduction in the divergence to the diffraction limit. Zh. éksp. Teor. Fiz. 116, 1941–1946 (December 1999)