MAXIMIZING OUTPUT POWER OF A LOW-GAIN LASER SYSTEM

Rigrod theory was used to model outcoupled power from a low-gain laser with pod accuracy. For a low-gain overtone cw HF chemical laser, Rigr od theory shows that a higher medium saturation yields a higher overal l overtone efficiency, but does not necessarily yield a higher measura ble power (power in the bucket). For low-absorption-scattering loss ov ertone mirrors and a 5% penalty in outcoupled power, the intracavity f lux and hence the mirror loading may be reduced by more than a factor of 2 when the gain length is long enough to saturate the medium well. For the University of Illinois at Urbana-Champaign overtone laser that has an extensive database with well-characterized mirrors for which t he Rigrod parameters go and It were firmly established, the accuracy t o which the reflectivities of high-reflectivity overtone mirrors can b e deduced by using measured mirror transmissivities, measured outcoupl ed power, and Rigrod theory is approximatly +/-0.07%. This method of a ccurately deducing mirror reflectivities may be applicable to other lo w-gain laser systems that use high-reflectivity mirrors at different w avelengths. The maximum overtone efficiency is estimated to be approxi mately 80%-100%.