| The dynamical theories of pulsed CO2 lasers have played an important role in analyzing the mechanism of pulsed CO2 laser system, exploring novel lasers with high performance, and optimizing the design of operational lasers. This dissertation conducts systematic theoretical study on dynamical processes of pulsed CO2 lasers. A lot of numerical calculation and analysis has been carried out. The major creative results are as follows:(1) A multifrequency dynamical model is established to describe dynamical processes of pulsed CO2 lasers at different pressures, taking account of the effects of the collision-dependent overlap of rotational lines, hot bands and sequence bands on the gain spectrum, and non-Lorentzian line overlap.(2) The experimental rules of multiatmosperic CO2 lasers are explained by the multifrequency dynamical model, that the laser build-up time and pulse width decrease with increase of the specific input energy or the output laser energy, and for a resonator without any dispersive element inside its broadband spectrum is smooth and continuous, and frequency dependent feedback in a resonator causes strong modulation on output laser spectrum.(3) The influence of the gas pressure, mixture ratio, filling factor, ambient temperature, mirror reflectivity on the performance of TE(A) CO2 lasers is analyzed by the multifrequency dynamical model. The optimum mirror reflectivities are obtained for the output pulse energy and the output peak power, respectively.(4) Substituting electric field equations for photon density equations of the multifrequency dynamical model, a computer model for injection locking of pulsed CO2 lasers is established, expanding the multifrequency dynamical theory of pulsed CO2 lasers.(5) A universal software tool is developed for the calculation of relative gain coefficient, peak gain spectrum, pulse transient characteristics, output frequency characteristics, and injection-locking characteristics of pulsed CO2 lasers.
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