Nonvolatile Reconfigurable Phase‐Change Metadevices for Beam Steering in the Near Infrared |
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Authors: | Carlota Ruiz de Galarreta Arseny M Alexeev Yat‐Yin Au Maciej Klemm Martin Cryan Jacopo Bertolotti C David Wright |
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Affiliation: | 1. College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, UK;2. Department of Electrical and Electronic Engineering, University of Bristol, Bristol, UK |
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Abstract: | The development of flat, compact beam‐steering devices with no bulky moving parts is opening up a new route to a variety of exciting applications, such as LIDAR scanning systems for autonomous vehicles, robotics and sensing, free‐space, and even surface wave optical signal coupling. In this paper, the design, fabrication and characterization of innovative, nonvolatile, and reconfigurable beam‐steering metadevices enabled by a combination of optical metasurfaces and chalcogenide phase‐change materials is reported. The metadevices reflect an incident optical beam in a mirror‐like fashion when the phase‐change layer is in the crystalline state, but reflect anomalously at predesigned angles when the phase‐change layer is switched into its amorphous state. Experimental angle‐resolved spectrometry measurements verify that fabricated devices perform as designed, with high efficiencies, up to 40%, when operating at 1550 nm. Laser‐induced crystallization and reamorphization experiments confirm reversible switching of the device. It is believed that reconfigurable phase‐change‐based beam‐steering and beam‐shaping metadevices, such as those reported here, can offer real applications advantages, such as high efficiency, compactness, fast switching times and, due to the nonvolatile nature of chalcogenide phase‐change materials, low power consumption. |
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Keywords: | beam steering phase‐change materials phased arrays photonic metadevices plasmonic metasurfaces reflectarrays |
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