Explosive absorption of a finite-diameter beam

An analysis is made of resonant absorption of an electromagnetic field due to a transition between excited, initially practically vacant energy states of molecules. Such absorption is manifested by an explosion and it occurs when the intensity of the field being absorbed exceeds a certain threshold value. The dependences of the threshold characteristics of such explosive absorption on the laser beam diameter and laser pulse duration are obtained. It is shown that at the moment of absorption the vibrational temperature of the system becomes different from the translational temperature. An analysis is made of the dynamics of explosive absorption in a vessel containing a gas, and also of the characteristics of such absorption in nonequilibrium systems.