Phase sensitive measurements in a nonlinear interferometer using four-wave mixing in Rubidium-85

PAC

Conventional interferometers make precision measurements by analyzing the position of interference fringes while nonlinear interferometers rely upon a sensitive measurement of phase difference. We detect this phase sensitivity using a correlated probe and conjugate beam that have undergone four-wave mixing inside a hot Rubidium-85 vapor cell. By placing a piece of glass into the path of the probe we observe a phase shift that indicates a successful nonlinear interferometer. We now plan to place into the probe path oils with known indices of refraction on plasmonic media and measure the resulting phase shifts. These results will then allow us to back-calculate an unknown material’s index of refraction simply by observing the phase shift with a level of sensitivity greater than conventional interferometers. Continued research in the field of interferometry utilizing nonlinear processes should provide even greater sensitivity in precision measurements and applications across a range of scientific disciplines.