EFFECT OF SPECTRAL MISMATCH IN OPTICALLY PUMPED MOLECULAR LASER-AMPLIFIERS

The effect of spectral mismatch in an optically pumped CF4 laser ampli fier has been studied using a rate equation approach. Our calculations indicate that the reduction in the amplifier extraction efficiency on account of a frequency mismatch between the CO2 pump laser and the CF 4 pumped transition can be effectively countered by operating the ampl ifier at increased pressure, This is particularly useful when amplifyi ng CF4 transitions for which the pump offset is low, i.e. less than 20 0 MHz, since fine-tuning of high power CO2 lasers in this detuning ran ge is rather difficult. Also, for a given value of pump detuning, ther e exists an optimum operating pressure and for larger pump detunings t his optimum value of pressure is higher.