Optical magnetic lens: towards actively tunable terahertz optics

Actively tunable bistable optical Yagi-Uda nanoantenna.

We propose and theoretically demonstrate a novel type of optical Yagi-Uda nanoantennas tunable via variation of the free-carrier density of a semiconductor disk placed in a gap of a metallic dipole feeding element. Unlike its narrowband all-metal counterparts, this nanoantenna exhibits a broadband unidirectional emission and demonstrates a bistable response in a preferential direction of the fa...

Highly tunable optical activity in planar achiral terahertz metamaterials.

Using terahertz time domain spectroscopy we demonstrate tunable polarization rotation and circular dichroism in intrinsically non-chiral planar terahertz metamaterials without twofold rotational symmetry. The observed effect is due to extrinsic chirality arising from the mutual orientation of the metamaterial plane and the propagation direction of the incident terahertz wave.

Terahertz chiral metamaterials with giant and dynamically tunable optical activity

Jiangfeng Zhou,1,* Dibakar Roy Chowdhury,1 Rongkuo Zhao,2 Abul K. Azad,1 Hou-Tong Chen,1,† Costas M. Soukoulis,2 Antoinette J. Taylor,1 and John F. O’Hara1,‡ 1Center for Integrated Nanotechnologies, Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA 2Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, ...

Magnetic field tunable terahertz quantum well infrared photodetector

Optical modulation of continuous terahertz waves towards cost-effective reconfigurable quasi-optical terahertz components.

We report optical modulation of continuous terahertz (THz) wave in the frequency range of 570-600 GHz using photo-induced reconfigurable patterns on a silicon wafer. The patterns were implemented using programmable illumination from a commercially-available digital light processing (DLP) projector. A modulation depth of 20 dB at 585 GHz has been demonstrated. Modulation speed measurement shows ...