Compact low power graphene-based Y-branch THz switch

A subwavelength terahertz plasmonic Y-branch switch based on graphene/gold hybrid structure is proposed. By controlling the graphene optical conductivity via modifying its chemical potential through a variable applied voltage, the real and imaginary parts of the effective refractive index of the hybrid structure can be controlled. Numerical results obtained from finite element method simulation show that THz wave incident upon the surface of the proposed structure excite surface plasmon that can propagate across the switching device whose length is subwavelength of the input wavelength. The device simultaneously provides advantages of compact size, low power and appropriate ON/OFF ratio.