Slow-light medium based on coupled erbium-doped fiber resonators : optical measurement of the phase shift
Résumé
The experimental demonstration of coupled resonator induced transparency has been made using passive fiber or WGM microspheres. The maximal group delay introduced depends mainly on the relative value of the intrinsic losses with respect to the value of the coupling between the resonators. Our experimental setup consists in two coupled Er3+ doped fiber resonators. By pumping each resonator independently, the values of the residual losses in the two resonators can be modified and the transparency maximized using the right pumping rate. We measure the phase shift produced by the coupled resonators and deduce the group delay.