Recent advances in solid fueled pulsed short-wavelength chemical laser research

Recent advances in the research aimed at achieving short-wavelength chemical laser via detonation of primary explosives are presented. Lead azide, Pb(N₃)₂, is initiated by a laser pulse and the ensuing chemiluminescence and laser induced fluorescence are monitored. As a result of the detonation, electronically excited N₂ is formed and a number of Pb states are preferentially populated by energy transfer from the N₂. Most of the chemiluminescence originates in Pb and appears in the time interval 5 -50 μs following the initiation, depending on the geometry of the detonation vessel. The temporal behavior is explained by a ”moving cloud” hydrodynamic model and by a coupled hydrodynamic-kinetic model. Calculations based on the coupled model point out that population inversion between potential laser levels of Pb is feasible. Both experiments and calculations indicate that high concentrations of excited, effectively long-lived Pb states are maintained as a result of radiation-trapping and that these states can be exploited to obtain laser transitions.