Photonic electromagnetically induced transparency and collapse of superradiant modes in Bragg multiple quantum wells

We show that infrared dressing of the superradiant excitons in a multiple-quantum-well photonic band gap structure can lead to photonic electromagnetically induced transparency. This process, which occurs via coherent control of the contributions of resonant excitonic features and background refractive index contrast of the barriers and wells, allows the probe field to pass through the structure in the vicinity of the Bragg wavelength without being affected by the index or absorption periodicity. We also show that the exciton infrared dressing can spatially shift the light wave pattern inside the crystal and destroy the superradiant mode of the structure. When the latter happens, the structure acts as a nonresonant passive photonic band gap, abandoning its excitonic features.