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A theoretical analysis is made of some features of the emission spectra of high-pressure CO2 lasers. Dependences of their spectral characteristics on the main parameters of lasers utilizing 12CO2 and 13CO2 molecules are determined. It is shown that simultaneous lasing due to several transitions is typically found for pulses of 1 μsec duration, whereas single-frequency lasing due to the P(20) transition for 12CO2 and due to the P(16) transition for 13CO2 may occur for longer pulses.

An experimental investigation was made of the energy, spectral, and time characteristics of the radiation emitted by a pulsed electron-beam-controlled laser utilizing mixtures of 12C16O2, 13C16O2, 12C18O2, and 12C16O18O molecules with a nonselective resonator operating in the quasi-cw regime. The replacement of one isotopic form of the carbon dioxide molecules with another made it possible to alter the initial frequency of the laser without a significant change in its energy characteristics.

An experimental study was made of the interaction of pulsed laser radiation at 10.6 μ wavelength with a plasma layer in argon. The plasma parameters were determined spectroscopically. In the unperturbed state its temperature was 1.4×104 °K, its electron density 3×1017cm−3 and its pressure 3 atm. It was established that under the influence of the laser radiation an observable plasma perturbation takes place at power densities exceeding 5×105 W/cm2. At power densities ~107 W/cm2 there appears a heated zone whose geometry is determined by the beam caustic and the absorption coefficient of the plasma. At higher power densities breakdown occurs in the cold gas near the plasma boundary. The breakdown pattern is similar to that observed in the interaction of radiation with a solid target.

Experimental and theoretical investigations were made of the operation of a cw continuous-flow electron-beam-controlled laser using a binary mixture of naturally occurring and isotopically modified carbon dioxide molecules. The replacement of 12C16O2 with 13C16O2 made it possible to alter the emission frequency without a significant loss in the output power and laser efficiency.

A study was made of the interaction between laser radiation and opaque targets. The energy radiated by a plasma jet resulting from this interaction was determined in a wide range of wavelengths (0.2–4 μ). The density of the incident laser power was ~106 or ~107 W/cm2 for the same size of spot on the target. The targets were Duralumin, ebonite, and graphite. The energy radiated by a plasma jet represented, depending on the target material and the nature of the interaction, from 20 to 50% of the incident laser energy. The experimental results were used to estimate the role of other factors in the energy balance of the interaction between laser radiation and matter.

Spark discharges on both sides of the main gap were used for the preionization of the gas in a 0.4-liter pulsed CO2 laser. The gap was formed by two monolithic metal electrodes. An output energy of 9 J was obtained at a pressure of 600 mm Hg for a CO2:N2:He =1:1:2 mixture.