PT-symmetric scatterers (Presentation Recording)

Parity-time (PT) symmetric complex structures can exhibit peculiar properties which are otherwise unattainable in traditional Hermitian systems. This is achieved by judiciously involving balanced regions of gain and loss. Here we investigate the scattering properties of PT-symmetric diffraction gratings. The presence of the imaginary potential can modify the light transport properties in their far field. This is an outcome of a local power flow taking place between the gain and loss regions in the near field. We show that for a certain gain/loss contrast, all the negative diffraction orders can be eliminated while the positive diffraction orders can be amplified.