Rate equation model for mid IR OPML having common pump and upper lasing level; Application to 12.8 µm emission from NH3

A five-state kinetic model has been used to obtain an analytical expression for the power output of an optically pumped molecular gas laser having a common pumped and upper lasing level. The theoretical estimates for the various operational parameters of an optically pumped NH
3
laser (like operating pressure range, optimum operating pressure, variation of these with NH
3
gain length, etc.) obtained from this model are in good quantitative agreement with experimental results.