Abstract
Population inversion on the transition in rubidium atoms produced by cw laser excitation at different wavelengths has been analyzed by comparing the generated mid-infrared radiation at 5.23 μm originating from amplified spontaneous emission (ASE) and isotropic blue fluorescence at 420 nm. Using a novel method for detection of two-photon excitation via ASE, we have observed directional co- and counter-propagating emission at 5.23 μm. Evidence of a threshold-like characteristic is found in the ASE dependences on laser detuning and Rb number density. The power dependences of the backward- and forward-directed emission can be very similar; however, their spectral dependences are not identical. A new type of temporally and spatially coherent radiation is suggested.
© 2017 Optical Society of America
Full Article | PDF ArticleMore Like This
Alexander M. Akulshin, Dmitry Budker, and Russell J. McLean
J. Opt. Soc. Am. B 34(5) 1016-1022 (2017)
Alexander M. Akulshin, Nafia Rahaman, Sergey A. Suslov, Dmitry Budker, and Russell J. McLean
J. Opt. Soc. Am. B 37(8) 2430-2436 (2020)
Yong Sup Ihn, Kwang-Kyoon Park, Yosep Kim, Young-Tak Chough, and Yoon-Ho Kim
J. Opt. Soc. Am. B 34(11) 2352-2357 (2017)