Dynamics of driven two-level systems with permanent dipole moments: an optical realization

Abstract

It is theoretically shown that the tunnelling dynamics of light between two sinusoidally curved coupled optical waveguides of different sizes exactly mimics the population dynamics of a two-level system with nonzero diagonal dipole matrix elements subjected to an applied sinusoidal electric field, thus realizing an optical analogue of a two-level dipolar molecule in an external ac field. Some characteristic dynamical features, including multi-photon transitions, sinusoidal population oscillations built up in a series of stair steps or square-wave population oscillations, are reproduced in the optical waveguide system. Design parameters for their observation are given with reference to lithium-niobate optical waveguides.