The nonlinear dynamics of a loss-modulated, two-wave CO2 laser lasing on vibrational–rotational lines of different vibrational bands has been investigated theoretically and experimentally. It is shown that the time and energy parameters of laser radiation can be controlled within fairly wide limits by changing the depth and frequency of modulation and the ratio between the constant components of the losses.

The nonlinear response of a CO2 laser to biharmonic loss modulation was theoretically investigated for tuning of the radiation frequency within the limits of the amplification band. It is shown that the value and form of the amplitude-detuning characteristic (and, consequently, the temporal and energy parameters of the laser radiation) can be controlled within sufficiently wide limits by changing the modulation frequency and the phase shift of oscillations.

The increase of frequency number generated by conventional CO2 laser systems is undoubtedly of interest for various applications associated with selective action on substance. Key Words: TEA CO2-laser0111–1110 hot band 12CO2 13CO2 and 14CO2 isotope modificationsuranium isotope separation.

An experimental and theoretical investigation was made of the small-signal gains of lines in the second sequence band, and of the temperature of the asymmetric ν3 mode of the CO2 molecule in a TEA CO2 amplifier as a function of the composition of the CO2–N2–He mixture. The optimal partial pressures of the component were determined. In a TEA CO2 amplifier with ultraviolet preionization provided by auxiliary lateral discharges it was found that the maximum gain of ∼0.01 cm-1 for the 10P(19) line of the second sequence band was achieved in a CO2:N2:He = 1:1:3 mixture.

Detailed experimental investigations of the kinetics of the vibrational and translational temperatures of the active medium of a TEA CO2 laser are reported for the first time. A comparison of the theoretical and experimental results confirms the validity of the generally adopted temperature model for times ≳1 μsec/atm after the start of the discharge. A considerable difference between the experimental and theoretical results in the range <1 μsec/atm shows that in this range a dynamic equilibrium is still absent between the lower levels of the symmetric and bending modes. A reduction discovered in the rate of transfer of vibrational energy from N2 to CO2 for excitation in an electric discharge is explained by the excitation of the higher vibrational levels of N2, a low VV relaxation rate in nitrogen, and anharmonicity of the N2 molecule.

The first production of magawatt-range output pulses in the wavelength internal 10.95--11.25 ..mu..m in a TEA CO/sub 2/ laser is reported. (AIP)

The first report is given of the realization of a TEA CO2 laser operating regime in which the emission spectrum contains simultaneously two frequencies belonging to lines of the 0001–[1000, 0200]I,II and 0002–[1001, 0201]I,II bands separated from each other by 0.2–0.6 cm−1. It was found that the use of partial-bleaching selective losses was a suitable method for realizing this regime. Radiation having these spectral characteristics can be applied to solve a number of problems involving selective interaction with matter and laser monitoring of the atmosphere.

It is shown theoretically that it is possible to achieve an efficiency of 5–15% for real TEA CO2 lasers emitting lines in the 0002–[1001, 0201]I,II bands. An energy of 1 J per pulse was achieved from a TEA CO2 laser, employing a double discharge tube, for the 10-μ P(17) line in this band. This is only a factor of three less than that for the lines of the regular band under the same conditions.