Numerical simulation of an N2O downstream mixing gasdynamic laser

A computer simulation of an N2O downstream mixing gasdynamic laser is made using the leaky stream tube approach. The numerical results show that the temperature rise due to mixing is significantly detrimental to the laser performance. In order to reduce the temperature rise, the area ratio of the N2O-He nozzle should be made large. However, the supersonic solution in the mixed stream does not satisfy the second law of thermodynamics at very large area ratio. Therefore, within the range of the present investigation, the laser performance is optimized at an area ratio of six. It is shown that a small signal gain coefficient of 2.25/m and the maximum available laser energy of 7.70 W/sq cm are attainable.