Abstract

We report the first observation of a cone radiation at 5890–5896 Å (ω_L) in sodium vapor pumped by an excimer laser–dye laser tunable over a 334–347-nm (ω_P) range. Simultaneously, with the cone radiation two tunable stimulated emissions were detected: the 3S–4S (Ω) stimulated electronic Raman scattering transition at 2.38–2.65 μm (ω_S), and the 4S–3P transition at 1.138–1.142 μm (ω_T). On the hollow ring of the upward cone radiation three spectral lines appear at 5890, 5896, and 5894 Å. The first two wavelengths are fixed and the third is slightly tunable during the tuning of the dye laser. The cone size varies with the sodium vapor pressure and it disappears, while the buffer argon pressure is higher than 20 Torr.

© 1986 Optical Society of America