The Plasma Laser:Population Inversion in Hydrogen Plasmas.

摘要

A rapidly recombining plasma preferentially populates the upper energy levels,thus producing population inversions. Laser devices in which the active medium is a recombining plasma are termed 'plasma'or 'recombination'lasers. A computer code was developed to determine the level populations of hydrogen as a function of time. The instantaneous cooling of the free electrons in a completely ionized hydrogen plasma was assumed. The resulting population inversion produced estimates of gain which were sufficient for laser action. The absorption of Lyman radiation in the plasma was also assumed. Generally,the effect of this absorption is to decrease the duration and magnitude of the gain. However,when the lower laser level and the ground level coincide,the resulting gain can be enhanced by this absorption. Comparison of the computer results shows reasonable agreement with other researchers'computer predictions. A cross-referenced bibliography is provided to assist in further study of plasma lasers. (Author)