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 NH3laser (like operating pressure range, optimum operating pressure, variation of these with NH3gain length, etc.) obtained from this model are in good quantitative agreement with experimental results.