Versatile Airy-Beam Generation Using a 1-Bit Coding Programmable Reflective Metasurface

The Airy beam, known to present particular unique features, such as diffraction-free, self-healing, and self-bending, has attracted considerable interest in recent years. Here, an electronically controlled reflec-tive coding metasurface is exploited to generate and dynamically manipulate the Airy beam over a wide frequency band in the microwave regime. By judiciously controlling the external dc bias voltage applied to the programmable metasurface, two distinct control states, 0 and 1, are engineered as digital codes for -pi/2 and +pi/2 phase responses, respectively. The programmable binary-phase-coding metasurface enables the generation and active reshaping of the Airy beam to be numerically simulated and experimen-tally validated. Moreover, the metasurface allows the bandwidth limitation of passive counterparts to be overcome and is able to modulate electromagnetic waves over a broad frequency range, spanning from 9 to 12 GHz, to realize diffraction-free Airy beams.