Nonlinear resonance in low-pressure gases not subject to drift broadening
Shalagin A. M.
The higher-order nonlinear-absorption resonances with respect to the radiation intensity are not subject to a drift broadening (broadening attributable to the finite time the absorbing particle spends in the light beam). This effect is due to the increased role of slow particles resulting from the increase of the degree of interaction nonlinearity. Starting with the third-order intensity, the nonlinear resonances retain the collision width at any low pressure.