Aluminum nitride emission from a laser-induced plasma in a dispersed aerosol

Emission from gas-phase AlN has been observed from a laser spark in a dilute suspension of AlN and Al nanoparticles in gaseous nitrogen. AlN emits most strongly in the 10-100-μs time period after laser excitation, and the emission is strong enough to be analyzed at moderately high dispersions. Under these high-temperature conditions, the population of high rotational levels results in there being a greater number of transitions than was observed by previous investigators, suggesting that the upper-state predissociation is fairly weak, and transitions over a much wider range of wavelengths are accessible for absorption-based diagnostics. The AlN emission is found to result primarily from the reaction of gas-phase nitrogen with vaporized aluminum.