Metasurface enabled quantum edge detection  December 29, 2020 Metasurfaces consisting of engineered dielectric or metallic structures provide unique solutions to realize exotic phenomena including negative refraction, achromatic focusing, electromagnetic cloaking, and so on. The intersection of metasurface and quantum optics may lead to new opportunities but is much less explored. An international team of researchers (China, USA – UC San Diego, Columbia University, Harvard University, Austria) proposed and experimentally demonstrated that a polarization-entangled photon source can be used to switch ON or OFF the optical edge detection mode in an imaging system based on a high-efficiency dielectric metasurface. This experiment enriches both fields of […]

Metasurface opens world of polarization

Science  Daily June 3, 2020 To achieve broad polarization manipulation, multiple birefringent materials need to be stacked one top of another making these devices bulky and inefficient. Researchers at Harvard University used topological optimization to design birefringent materials. They started with the functionality of the metasurface and allowed the algorithm to explore the huge parameter space to develop a pattern that can best deliver that function. The resulting metasurface was composed of nested half circles. The odd shapes have opened a whole new world of birefringence. They can achieve broad polarization manipulations; polarization can be tuned by changing the angle […]

Smart metamaterials that sense and reprogram themselves  November 11, 2019 As proof of concept, an international team of researchers (USA – Duke University, UK, China) proposed and developed a smart digital-coding metasurface with self-adaptive capacity for reprogrammable functionality. A sensor on the metasurface detected specific features surrounding the construct in the environment and delivered them to a microcontroller unit (MCU) which independently determined reactions to these variations and then instructed the FPGA via coding patterns, to change the metasurface configuration in real time. The smart metasurfaces achieved self-adaptive reprogrammable functionality automatically based on the surface-installed sensing-feedback system and calculation software. The team envisions the preliminary work […]

‘Folded’ optical devices manipulate light in a new way October 31, 2018 In metasurface-based optical systems, most of the total volume inside the device is just free space through which light propagates between different elements. Free space makes it difficult to scale down the device. To overcome this limitation, a team of researchers in the US (Caltech, UMass Amherst) has introduced a technology called “folded metasurface optics,” which is a way of printing multiple types of metasurfaces onto either side of a substrate making the substrate itself a propagation space for the light. They demonstrated the technique by building a spectrometer. The folded metasystem design can be applied […]