Broadband terahertz modulation using subwavelength metallic slit arrays

Broadband modulation of freely propagating terahertz waves at room temperature is demonstrated using subwavelength metallic slit arrays. These devices enable the control of the extraordinary terahertz transmission through the metallic films by changing the geometrical parameters of the arrays. Our designs achieve an intensity modulation depth of 65% and modulation bandwidth of 2 THz. Implementation of these devices with micro-electro-mechanical fabrication techniques can led to very high modulation speeds.