Optics Express
Light propagation through an atomic vapor in the presence of a magnetic field of arbitrary direction: taking the non-orthogonality of the electric field modes into account
Jack D. Briscoe, Danielle Pizzey, R. M. Potvliege, Steven A. Wrathmall, Ifan G. Hughes
Abstract
Alkali-metal atomic vapors are the foundation of an ever-growing range of applications, driven by a comprehensive understanding of their interaction with light. We focus on the case of a vapor interacting both with a low intensity laser field and an external magnetic field of an arbitrary direction with respect to the laser field propagation axis. Such a medium exhibits two electric field modes that, in general, are non-orthogonal. Mode non-orthogonality is currently neglected by the models used in this context. We derive a light propagation formalism which takes into account the non-zero overlap of the two modes. We verify the theory using weak-probe spectroscopy of the Rb D 2 line, showing excellent agreement with the experiment. The predictions of the theory can be exploited, and optimized, to design better atomic photonic devices.