Radiative Collisions in a Strong-Field Regime

Abstract

The observation of radiative collisions in the strong-field regime is reported, specifically the multiphoton-microwave-assisted resonant collisional energy-transfer process $\mathrm{Na}\mathrm{}\left(\mathrm{ns}\right)+\mathrm{Na}\mathrm{}\left(\mathrm{ns}\right)\mathrm{}\to \mathrm{Na}\mathrm{}\left(\mathrm{np}\right)+\mathrm{Na}\mathrm{}\left(\right(n-1\mathrm{}\left)p\right)+mh\nu$, where $m$ is as high as 4. By use of a "dressed-atom" approach in a low-frequency (or adiabatic) approximation, a theoretical interpretation valid for the strong-field regime is given which is in good agreement with the present experimental results.