Slow light via tunneling induced transparency in quantum well heterostructures

We investigate the possibility of slowing down terahertz light via intersubband transitions in quantum well heterostructures. The slow-down effect is achieved via tunneling induced transparency in a three level Λ-system by careful engineering of the wave functions. The inherently short coherence times in such solid state media inevitably leads to strong absorption of the signal, which we propose to compensate for by incorporating a quantum cascade amplifier (QCA) into the system.