Observation of Magnetochiral Birefringence

We report the observation of magnetochiral birefringence in a ring laser configuration for two different chiral compounds. Such a setup allows isolation of true magnetochiral variation of the refractive index independent of associated polarization effects. The change in refractive index $\Delta n$ is measured to be ${10}^{-10\mathrm{}}$ in limonene at 488 nm with a magnetic field of 1.3 kG. This value, characterizing the fundamental magnetochiral anisotropy, is in agreement with earlier theoretical predictions.