Electrically switchable metamaterial analogue to electromagnetically induced transparency

In this paper, we propose an active electromagnetically induced transparency-like (EIT-like) metamaterial to investigate the electrically switchable behaviors. The EIT-like metamaterial is constructed by a "bright" combline resonator side-coupled with a "dark" split-ring resonator. The "bright" and "dark" resonators are individually or simultaneously soldered with PIN diodes. The diodes are connected with DC voltage sources through conducting wires. By adjusting the bias voltage within the range of 0.0-1.2 V, the resistance of PIN diode can be changed from 9000 to 1 Omega, thereby dynamically modulating the EIT-like spectrum. Both simulation and experiment results indicate that this active configuration can generate remarkable multi-band amplitude modulations on the EIT-like spectrum, and a significant modulation depth of up to 18.3 dB was achieved on the tested transmission through the metamaterial. Moreover, the transformation of transparency-to-absorption and slow light on-to-off switching actions are also obtained via electric biasing the proposed sample. These findings resulted from the EIT-like mechanism, which may promote the development of actively controlled photonic devices.