InSb-based tunable terahertz directional beaming device

• An active tunable THz directional beaming device based on InSb is proposed.
• The deflection angle increases with the increment of temperature.
• The deflection angle decreases as magnetic field increases.
• The deflection angle could reach 45.5° for 0.65 THz at 220 K and 0.6 T.
• The proposed device could work as an ideal THz beam splitter.

A single-side InSb-dielectric surface grating structure has been proposed to realize active tunable terahertz directional beaming. In consideration of the magneto-optical property of InSb, the influences of applied magnetic field as well as environmental temperature on directional beaming characteristics of our proposed device have been numerically simulated. Simulation results indicate that the deflection angle increases with the increment of temperature while it tends to decrease as applied magnetic field intensity increases, therefore tunable directional beaming could be achieved within the terahertz frequency range. For the respective environmental temperature and applied magnetic field intensity of 220 K and 0.6 T, the deflection angle could reach 45.5° at 0.65 THz. Moreover, under the same temperature and magnetic field, the deflection angles are different for the incident waves with different frequencies, which indicates that the proposed device could serve as an ideal THz beam splitter.