From a nonaqueous alkali-metal salt solution, it is possible to observe sonoluminescence (SL) at low acoustic drive levels with the ratio of the acoustic pressure amplitude to the ambient pressure being about 1. In this case, the emission has a narrowband spectral content and consists of a few flashes of light from a levitated gas bubble going through an unstable motion. A systematic statistica...

The analysis of the spectra of the noble atmospheric gases, utilizing descrip tive daLa cove ring the photographicall y accessible region, has long indicated the possibili ty of a considerable ex te nsion of most of t hese spectra into the infrared r egion beyond 1.3 microns. Obse r vations of the spectra of krypton a nd a rgo n, in the region be tween 1 and 2 mi crons, have bee n made with a P...