Mapping the near-field dynamics in plasmon-induced transparency

The photonic analog of atomic electromagnetically induced transparency (EIT) introduces a sharp resonance in transmission within a broad absorption profile. The rapid dispersion of these structures leads to critical photonic applications such as integrated optical delay lines. To date, experimental demonstrations of such analogs have relied on the measurement of the far-field spectrum. Here we present a near-field optical study of plasmon-induced transparency (PIT), a photonic analog with subwavelength-sized plasmonic resonators mimicking the bright and dark elements in EIT. Supported by numerical analyses, the optical near-field distributions at various wavelengths reveal the interference dynamics between the coupled bright and dark plasmonic resonators.