Stimulated emission in Rydberg Matter - a thermal ultra-broadband tunable laser

A tunable laser is built with the condensed excited material Rydberg Matter as the active medium. It is tunable over at least 0.9-16 mum in the infrared. The tuning is almost continuous over this range, due to the broad bands for the forbidden transitions in Rydberg Matter. The beam divergence is low, <10 mrad. The gain for a single pass is 3-7 depending on wavelength. The bandwidth has in some experiments been decreased to 5 cm(-1). Absorption spectra are shown both for liquid and gaseous samples. The excitation is purely thermal. (C) 2003 Elsevier B.V. All rights reserved.