Independently tunable double electromagenetically induced transparency-like resonances in asymmetric plasmonic waveguide resonator system

Double electromagnetically induced transparency (EIT)-like resonances are numerically achieved by detuning and bright-dark coupling in an asymmetric plasmonic waveguide resonator system. The transmission properties of the system are simulated by the finite-difference time-domain (FDTD) method. Just because double EIT-like resonances originate from different mechanisms, a single EIT-like resonance can be well tuned independently, namely, one induced transparency window can be tuned in the horizontal direction while the other one is nearly invariable. The present design idea will be applicable in highly integrated optical circuits. Moreover, the formation of double EIT-like resonances may play a guiding role when designing plasmonic devices.