Temporal analogs of electromagnetically induced transparency, induced absorption, and Fano resonance.

We describe the occurrence of electromagnetically induced transparency (EIT), electromagnetically induced absorption (EIA), and Fano resonance due to time-controlled discontinuities in the refractive index of a medium, which leads to the formation of a double-cavity system inside a temporal photonic crystal. The temporal resonances partly resemble the optical resonances arising in conventional microcavities, since the amplified temporal EIA displays distinct spectral characteristics. Although an amplified EIT does not occur, a strongly amplified EIA affects the behavior of EIT as well. Besides modifying the temporal resonances via coupled-cavity interactions, we reveal refractive index-controlled temporal resonances. This computational study paves the way to probe the temporally driven coherent phenomena of EIT and EIA with potential applications such as slow-light, amplified fast-light, amplified ultranarrow bandwidth optical filters, and multicavity systems.