Two-photon resonant, optical third-harmonic generation in cesium vapor

Abstract

Resonant enhancement of optical third-harmonic generation in cesium vapor has been observed when twice the energy of the fundamental photon becomes equal to the energy difference between the $9d{}_{}{}^2{}_{}{}^{}D_{\frac{3}{2}}^{}{}_{}{}^{}$ level and the ground state of the cesium atom. The measured, effective coefficient is ${10}^{-30\mathrm{}}$ esu/atom, which is more than a factor ${10}^8$ larger than the corresponding coefficient for the helium atom. An effective coefficient is synthesized by first calculating the coefficient for a single cesium atom at rest and then including the effects of Doppler broadening and the fundamental laser spectrum. The calculated value is in satisfactory agreement with experiment.