Review of theoretical gain-optimization studies in 10.6µm CO2-N2 gasdynamic lasers

A comprehensive theoretical analysis of optimization of gain in CO₂-N₂ gasdynamic laser employing wedge or conical or hyperbolic nozzles with either H₂O or He as the catalyst is presented. After a review of previous work, the usual governing equations for the steady inviscid quasi-one-dimensional flow in a supersonic nozzle of a gasdynamic laser are used to obtain similar solutions for the various flow quantities, which variables are subsequently used to optimize the small-signal gain on theP(20) line of the (001) → (100) transition of CO₂ at wavelength 10.6μm. The corresponding optimum values like reservoir pressure and temperature and nozzle area ratio also have been predicted and presented in the form of graphs. The analysis predicts that employing of 2D-wedge nozzle results in higher gain values and the CO₂-N₂-H₂O gasdynamic laser employing 2D-wedge nozzle is operationally the best laser system for which the optimum value as high as 3.1 m⁻¹ gain can be obtained.