Enhancement of magneto-optic effects via large atomic coherence in optically dense media

We utilize the generation of large atomic coherence in optically dense media to enhance the resonant nonlinear magneto-optic effect by several orders of magnitude, thereby eliminating power broadening and improving the fundamental signal-to-noise ratio. A proof-of-principle experiment is carried out in a dense vapor of Rb atoms. Applications such as optical magnetometry, the search for violations of parity and time-reversal symmetry, and nonlinear optics at low light levels are feasible.