DYE-DEPENDENCE OF THE 830NM AND 1.16-MU-M EMISSIONS IN SODIUM VAPOR PUMPED NEAR THE 3S-4D 2-PHOTON RESONANCE

Abstract

The 830 nm and 1.16 mum emissions in sodium vapor which is pumped near 3S-4D two-photon resonance have been observed. It has been found that these two emissions are induced by the spontaneous emission of the dye R590, that provides the emissions near 584 nm, which as idle photons are coupled to the 830 nm and 1.16 mum emissions in the axially phase-matched six-wave mixing processes. This conclusion is based on the fact that the observed 830 nm and 1.16 mum emissions will almost disappear if the spontaneous emission of the dye R590 in the 584 nm wavelength range is blocked. As a result, the fluctuation and band-like structure in the emission spectra of the 830 nm and 1.16 mum lines can be understood to be due to the broad band and fluctuating in the spontaneous emission of the dye R590, and also due to the amplification in these generation processes that makes many unstable peaks in their spectra.