Observation of picosecond UV pulses produced by coherent scattering of IR femtosecond pulses in atomic rubidium vapor

Abstract

We report the observation of coherent UV light pulses by the coherent scattering of IR pulses from atomic rubidium vapor. Rubidium atoms were first excited by a 100 fs pulse from the 5S ground state to the 5D state via a two-photon transition. The atoms were then pumped by an IR pulse resonant to the 5D–12P transition. The presence of the IR pulse triggered the instantaneous emission of a UV light pulse on the 12P–5S transition. The pulse had a time duration of tens of picoseconds, which was measured by a picosecond-resolution streak camera. The temporal shape of the generated light is explained by a simplified atom–field interaction theory.