A sealed high-repetition-rate TEA CO2 laser

The operation of a compact atmospheric-pressure high-repetition-rate (100 pulse/sec) TEA-CO2 laser using the double-discharge excitation technique of Laflamme (1970) with a dielectrically encapsulated trigger bar is demonstrated. Mass spectroscopic measurements of the gas mixture reveal that sealed laser operation is possible in a H2-N2-CO2 gas mixture provided that the oxygen concentration is less than about 1 to 2%. It is theoretically shown that about 2% O2 increases significantly the negative-ion population. Addition of small amounts of H2 and CO keep the oxygen concentration below 2% by reducing the CO2 decomposition for a successful sealed laser operation. Experimental results are compared with theoretical predictions of a model involving neutral and negative-ion processes.