Bessel beams generation with biphase transition of vanadium dioxide metasurface

Bessel beams are highly attractive due to their non-diffraction properties, parallel processing capabilities, and large capacity. However, conventional methods for generating Bessel beams, such as using spatial light modulators, axicons, and diffraction optical elements, face limitations in terms of system complexity, bulkiness, low uniformity, and limited numerical aperture (NA). In this work, we exploited the phase change material vanadium dioxide (VO2) to generate both transmitted and reflected Bessel beams. Moreover, the self-healing property of Bessel beams was verified. Our resultsreveal that VO2 in the insulating state achieves a transmittance of 85% in the transmitting mode, while VO2 in the metallic state exhibits a reflection efficiency of 77% in the reflecting modeThis performance indicates the potential applications in efficient switchable metasurfaces.