Oblique metal gratings transparent for broadband terahertz waves

In this work, we experimentally and theoretically demonstrate that oblique metal gratings with optimal tilt angles can become transparent for broadband terahertz waves under normal incidence. Direct imaging is applied to intuitively prove this broadband transparency phenomenon of structured metals. The transparency is insensitive to the grating thickness due to the non-resonance mechanism, and the optimal tilt angle is determined only by the strip width and the grating period. The oblique metal gratings with broadband transparence may have many potential applications, such as transparent conducting panels, white-beam polarizers, and stealth objects. (C) 2013 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.