We demonstrate a multiband background-free terahertz (THz) switch in photoactive chiral metamaterial using polarization conversion. Orthogonal arrangement of two asymmetrical split-ring apertures allows a high polarization conversion efficiency and low copolarization transmission. The chiral metamaterial embedded with photoactive silicon promises a dynamic control on cross-polarization transmission and thus enables an efficient background-free THz switch. The on/off state of THz metamaterial switching can be efficiently controlled by an optical pump. The realization of a cross-polarization THz switch provides a new mechanism of mode switching to control THz wave propagation and will be a promising candidate for polarization devices.
© 2014 Optical Society of America
Original Manuscript: February 21, 2014
Revised Manuscript: April 14, 2014
Manuscript Accepted: April 17, 2014
Published: May 15, 2014
T. T. Lv, Z. Zhu, J. H. Shi, C. Y. Guan, Z. P. Wang, and T. J. Cui, "Optically controlled background-free terahertz switching in chiral metamaterial," Opt. Lett. 39, 3066-3069 (2014)