Two-Photon Laser

Abstract

We have demonstrated a pulsed two-photon laser at the transition $3d^{2}D\ensuremath{-}2s^{2}S$ of atomic Li (frequency ${\ensuremath{\omega}}_{31}$) by (i) generation of a coherent light beam at ${\ensuremath{\omega}}_{x}$, stimulated by light pulses at ${\ensuremath{\omega}}_{1}={\ensuremath{\omega}}_{31}\ensuremath{-}{\ensuremath{\omega}}_{x}$, and (ii) single-pass amplification of injected light at ${\ensuremath{\omega}}_{3}=\frac{{\ensuremath{\omega}}_{31}}{2}$.