Sunday, July 20, 2014
Abstract-Capture of a terahertz wave in a photonic-crystal slab
With many potential applications in mind, great effort is being applied to develop a terahertz-wave technology platform on which waves can be manipulated with sufficient confinement and efficient interaction for the development of smart components. Here, we utilize the in-plane resonance of a thin, planar photonic-crystal slab with negligible absorption loss to successfully demonstrate and visualize terahertz-wave trapping. We artificially introduce free carriers, which interact with the trapped waves, and capture them in the slab by absorption. Our system exhibits an experimental absorptivity (interaction efficiency) of ∼99% and a broad bandwidth (absorptivity of ≥90%) that covers 17% of the centre frequency. We also demonstrate its application to the stabilization of terahertz wireless communication systems. Our study shows the capability of photonic crystals as a terahertz-wave platform, the application of which may be extended to other components including filters, couplers, antennas, detectors, modulators, switches and emitters.