Reaching dark mode condition in a system of gain-loss assisted coupled resonators

International audience; A generic model of two antennas type dissimilar resonators coupled both via near-field and far-field coupling with active gain and/or loss media is considered. Conditions required for hitting the dark mode operation are established. It is shown that tuning the material gain level is effective in cancelling the detrimental effect of deviations from nominal values of resonant elements unavoidably caused by fabrication imperfections. The considered approach can be used for the implementation of high-contrast tunable metasurfaces.