Laser gain measurements by means of amplified spontaneous emission

Laser gain determination by means of amplified spontaneous emission is discussed in terms of a rate-equation approach. Numerical solutions show that optical gain can be deduced only for a limited regime of experimental parameters. The theoretical analysis is examined with experimental gain data for organic dyes in the vapor phase and in liquid solution. In addition, the gain of electron-beam-excited Ar-N(2) and XeF laser mixtures has been studied.