Dielectric metasurfaces have achieved great success in realizing high-efficiency wavefront control in the optical and infrared ranges. Here, we experimentally demonstrate several efficient, polarization-independent, a...Dielectric metasurfaces have achieved great success in realizing high-efficiency wavefront control in the optical and infrared ranges. Here, we experimentally demonstrate several efficient, polarization-independent, all-silicon dielectric metasurfaces in the terahertz regime. The metasurfaces are composed of cylindrical silicon pillars on a silicon substrate, which can be easily fabricated using etching technology for semiconductors. By locally tailoring the diameter of the pillars, full control over abrupt phase changes can be achieved. To show the controlling ability of the metasurfaces, an anomalous deflector, three Bessel beam generators, and three vortex beam generators are fabricated and characterized. We also show that the proposed metasurfaces can be easily combined to form composite devices with extended functionalities. The proposed controlling method has promising applications in developing low-loss, ultra-compact spatial terahertz modulation devices.展开更多
基金National Basic Research Program of China(2014CB339800)National Natural Science Foundation of China(NSFC)(61420106006,61422509,61605143,61622505,61675145,61735012)+2 种基金Program for Changjiang Scholars and Innovative Research Team in University(IRT13033)Major National Development Project of Scientific Instruments and Equipment(2011YQ150021)Guangxi Key Laboratory of Automatic Detecting Technology and Instruments(YQ17203)
文摘Dielectric metasurfaces have achieved great success in realizing high-efficiency wavefront control in the optical and infrared ranges. Here, we experimentally demonstrate several efficient, polarization-independent, all-silicon dielectric metasurfaces in the terahertz regime. The metasurfaces are composed of cylindrical silicon pillars on a silicon substrate, which can be easily fabricated using etching technology for semiconductors. By locally tailoring the diameter of the pillars, full control over abrupt phase changes can be achieved. To show the controlling ability of the metasurfaces, an anomalous deflector, three Bessel beam generators, and three vortex beam generators are fabricated and characterized. We also show that the proposed metasurfaces can be easily combined to form composite devices with extended functionalities. The proposed controlling method has promising applications in developing low-loss, ultra-compact spatial terahertz modulation devices.
