Broadband Light Bending with Plasmonic Nanoantennas

School of Electrical and Computer Engineering and Birck Nanotechnology Center, Purdue University, West Lafayette, IN 47907, USA.
Science (Impact Factor: 33.61). 12/2011; 335(6067):427. DOI: 10.1126/science.1214686
Source: PubMed


The precise manipulation of a propagating wave using phase control is a fundamental building block of optical systems. The wavefront of a light beam propagating across an interface can be modified arbitrarily by introducing abrupt phase changes. We experimentally demonstrated unparalleled wavefront control in a broadband optical wavelength range from 1.0 to 1.9 micrometers. This is accomplished by using an extremely thin plasmonic layer (~λ/50) consisting of an optical nanoantenna array that provides subwavelength phase manipulation on light propagating across the interface. Anomalous light-bending phenomena, including negative angles of refraction and reflection, are observed in the operational wavelength range.

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    • "conductors) and dielectric materials, have opened up a new window of opportunities for applications in nanophotonic integrated circuits [7–13], surface-enhanced optical spectroscopy [14–16], energy harvesting [17–19], and super-resolution optical imaging [20, 21]. Advancements in transformation optics and nanofabrication techniques (both " top-down " lithography and " bottom-up " chemical synthesis/self-assembly) have also boosted many other applications associated with the intriguing properties of plasmonic metamaterials [22] [23] [24] [25] [26] [27] [28]. While some of the applications can be fully accomplished with passive plasmonic nanostructures that exhibit constant optical response, it requires reconfigurable or tunable SPs, which is known as active plasmonics [29], to develop other applications such as plasmonic switches [30] [31] [32] [33], plasmonic modulators [34] [35], and tunable color filters [36] [37]. "
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