Saturation in heteronuclear photoassociation of 6Li7Li -: art. no. 061403

We report heteronuclear photoassociation spectroscopy in a mixture of magneto-optically trapped Li-6 and Li-7. The laser-induced decrease in the Li-7 steady-state particle number, only appearing in the presence of Li-6, gives clear evidence of photoassociation to form (LiLi)-Li-6-Li-7. Hyperfine resolved spectra of the vibrational level v = 83 of the singlet state A(1)Sigma(u)(+) have been taken up to intensities of 1000 W/cm(2). The absolute resonance frequencies and the rotational constant have been measured. Saturation of the photoassociation rate has been observed for,two hyperfine transitions, which can be shown to be due to saturation of the rate coefficient near unitarity limit. Saturation intensities on the order of 40 W/cm(2) can be determined.