Optical Control of Collisional Interactions in $^{6}$Li using Dark Molecular States

We are developing ``dark-state'' two-optical field methods to control interactions in $^{6}$Li. Although external magnetic fields are typically used to tune the interaction strength in fermionic atoms near a Feshbach resonance, optical tuning methods can provide rapid temporal control and high-resolution spatial control thus enabling the study of non-equilibrium strongly interacting Fermi gases. However, optical tuning suffers from heating due to spontaneous scattering, which can be suppressed by a second optical field. We will report on the measurement of loss spectrum as a function of magnetic field and laser detuning near Feshbach resonances in $^{6}$Li and our progress on two-optical field loss suppression.