Coupled-resonator-induced transparency in a fiber system

Mode splitting in two coupled fiber-ring resonators is observed. We observe a cancellation of on-resonance absorption, which can be interpreted as resulting from the destructive interference of the symmetric and anti-symmetric modes of the system, in analogy with electromagnetically-induced transparency in atoms. The response of the system is characterized according to the degeneracy and distinguishability of the normal modes. Finite-difference time-domain simulations agree with an analysis of the transient response of the intra-cavity fields, and reveal coherent oscillations of the photons between the resonators, i.e., under-damped Rabi oscillations, which we predict to occur for distinguishable mode splittings.