Optically controlled light-pulse propagation in closed-loop configuration with saturable erbium-doped fiber

Abstract

We report experimental results on the 1550 nm modulated light propagation in a closed-loop all-fiber resonance configuration, which includes a segment of the erbium-doped fiber with saturable optical absorption. It is shown that by a simple increase of the average incident light power, one can switch from the undercoupling to the overcoupling with the closed-loop cavity, which leads to a dramatic change from advancement to delay in the transmitted optical signal with the resonance carrier frequency. In the reported experiments with the ≈4.4 m long closed-loop cavity (with a 2.4 m long EDF segment) we observed a switch from ≈0.26 fractional advancement to ≈0.65 fractional delay in 166 ns periodic light pulses with a resonance frequency in the 1550 nm wavelength range when the average incident power was changed from 0.09 to 0.6 mW.