“…Optical control of interactions in an ultracold gas offers tantalizing possibilities for creating "designer" two-body interactions. Unfortunately, previously reported optical methods [2,3,4,5,6,7,8,9,10,11,12] suffer from spontaneous scattering which limits the tunability of interactions. This dissertation reports on the demonstration of new optical methods that uses two optical fields to control interactions near collisional (Feshbach) resonances while suppressing spontaneous scattering by destructive quantum interference.…”