Broadband generation of abruptly autofocusing terahertz ring-Airy beams with all-silicon metasurface

•All-silicon metasurface is designed for broadband generation of THz ring-Airy beams.•Transmission efficiencies of metasurface at different frequencies are over 51.18%.•Focal length of the generated beam is positively proportional to the frequency.•Abruptly autofocusing property is positively related with the frequency.•Full width at half maximum of the focus is negatively related with the frequency.