LASER SPECTROSCOPY OF ATOMS GUIDED BY EVANESCENT WAVES IN MICRON-SIZED HOLLOW OPTICAL FIBERS

We report the first laser spectroscopic experiments on the Rb beam gui ded by blue-detuned evanescent waves in micron-sized hollow fibers. Th e two-step photoionization spectra show the long-range dispersive prop erties of dipole interaction between guided atoms and evanescent waves . A large enhancement factor of 20 in in the transmitted atomic flux i s obtained at optimal conditions and the total guidance efficiency is estimated to be above 40%. The state- and species-selective guide with proper frequency detunings of the guide laser realizes in-line spatia l separation of two stable Rb isotopes.