Abstract Described is the application of a matrix form of the continued fraction technique to the calculation of the velocity dependent force experienced by a multi-level atom interacting with a complex optical field. Unlike other techniques, this approach provides a solution which is valid for a wide range of optical field configurations and atomoc velocities and which includes the effects of both single and multi-photon processes. As a specific example of this technique the force experienced by a three-level atom (V) in a bichromatic light field is calculated.
It is shown that nonlinear interaction between two-level atom and the radiation field can profoundly modify the optical force experienced by the atom The dynamic stark shift now provides a cooling force even at zero detuning.Due to two-photon interaction the 'radiation pressure force' experienced by the atom is twice as large as that for one-photon case, consequently temperatures much lower than the one-photon limit can be achieved Keywords Two-photon interaction, laser cooling, optical force
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 ${\ensuremath{\lambda}}_{\mathrm{SW}}$=1.064 \ensuremath{\mu}m for the light force, we measured the polarizability of rubidium at this wavelength to be \ensuremath{\alpha}(${\mathrm{\ensuremath{\omega}}}_{\mathrm{SW}}$)=114\ifmmode\pm\else\textpm\fi{}9 A
˚3 (\ensuremath{\sigma}). Conversion of this ac polarizability to a static value using a semiempirical formula gives a value of ${\mathrm{\ensuremath{\alpha}}}_{\mathrm{dc}}$=52 A
˚3, within 10% of the best published experimental results.