In one minute

Gu, Singh, Liu, Zhang, Ma, Zhang and colleagues work with metamaterial analogues of electromagnetically induced transparency, which give classical structures features of quantum optical systems. Such analogues promise slow-light units, highly sensitive sensors and nonlinear devices. Optical control of this effect matters for optical networks and terahertz communications. They achieve active optical control of this transparency by tuning the metamaterial's dark mode. Photoconductive silicon in each unit cell lets ultrafast optical pulses switch the transparency window strongly, giving optically tunable group delay for terahertz light. This opens the way to chip-scale ultrafast devices for optical buffering and active terahertz filtering.

Active control of electromagnetically induced transparency analogue in terahertz metamaterials