SPECTRAL-LINE BROADENING FROM INDUCED RADIATIVE PROCESSES IN SOFT-X-RAY LASER-AMPLIFIERS

A one-dimensional model for the propagation of amplified spontaneous emission and a set of line-broadening equations for the frequency dependence of gain coefficients in the laser field are solved self-consistently. Results are presented for high-gain amplification from spontaneous emission, without and with saturation, and for injection into power amplifiers. Power broadening and Rabi splitting is seen to limit the effective gain-length product in high-gain collisionally excited neonlike lasers and to prevent some of the expected gain narrowing. For future power amplifier experiments, using high-gain preamplifier output fluxes as input, a general decrease in power gain is predicted. Rabi splitting of the output spectrum is expected, if power broadening is comparable to or larger than the intrinsic line broadening.