  We present a novel method for reducing the inhomogeneous frequency broadening
in the hyperfine splitting of the ground state of optically trapped atoms. This
reduction is achieved by the addition of a weak light field, spatially
mode-matched with the trapping field and whose frequency is tuned in-between
the two hyperfine levels. We experimentally demonstrate the new scheme with Rb
85 atoms, and report a 50-fold narrowing of the rf spectrum.
