| The use of CO2differential absorption LADAR (Laser Detection and Ranging) foratmospheric environment monitoring has been widely investigated and used due to itsadvantages of rapid alarm, high detecting sensitivity, long operational distance, largedetecting area, etc. A TEA CO2laser works in the9~11μm region of the spectrum, inwhich characteristic absorption lines of most atmosphere pollutants lie. It works in theatmospheric “transparency windows” and is safe for human eyes. A TEA CO2laser isan idea optical source and a core part of CO2laser differential absorption LADAR.In the theory part of this paper, the energy levels of a CO2molecule and the TEACO2laser excitation process are summarized; secondly, research on gains ofsmall-signals of TEA CO2laser and laser energy output efficiency is presented.Afterwards, the six-temperature model of laser is discussed, and scenario analysis of theformation of the laser output power under different conditions has been undertaken;finally, the tuning methods for TEA CO2laser have been summarized.In the design part of this paper, the design of the TEA CO2laser system structureand key components in the system are introduced; the laser components and someimportant parameters are discussed then, which is the basis for further research; finally,a miniature TEA CO2laser is taken as an example, which takes the first class of Ernstelectrode, spark discharge array ultraviolet pre-ionization, LC inversed circuit asexcitation power supply, and a gas mixture of CO2, N2and He as the working medium.In the experiment part of this paper, the environment for the experiments are firstlyset up; then in the case of free oscillation, the laser output energy, the wave pattern ofthe beam pulse and the output faculae under different conditions have been measured; inthe end, under the condition of manual tuning, spectrum of the TEA CO2laser output ismeasured, combined with the experiment results, further discussions and analyses. |
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