Recent advances in femtosecond optical vortices (FOVs)—characterized by helical wavefronts and high peak power—have enabled breakthroughs in attosecond vortex generation and 3D chiral microfabrication ...

(top) Time-varying average frequency of the denoised GPR profile. Green segments denote the wedges of buried polygons. (bottom) Stacked amplitude spectrum produced by summing the time-varying average ...