Light-force technique for measuring polarizabilities

We have developed a light-force technique for measuring polarizabilities. This new method uses the polarizaton forces experienced by an atom in the intense, inhomogeneous electric field of a standing-wave laser to deduce the polarizability. Using a Nd:YAG laser at λSW=1.064 {μ}m for the light force, we measured the polarizability of rubidium at this wavelength to be {α}(ωSW)=114±{}9 A³ ({σ}). Conversion of this ac polarizability to a static value using a semiempirical formula gives a value of αdc=52 A³, within 10% of the best published experimental results.