Fig. 6: Programmable terahertz (THz) vortex beam generation.
From: Photonic terahertz phased array via selective excitation of nonlinear Pancharatnam-Berry elements
a Schematic of the photonic THz phased array (PTPA) functionality on THz vortex beam generation. b, d Digital Micromirror Device (DMD) coding patterns to achieve helical phase distributions of topological charges |l | = 1 and |l | = 2, which are denoted as case 6 and case 7, respectively. c, e Equivalent phase distributions induced by the DMD coding patterns in b, d. f, h and g, i Calculated and measured transverse intensity and phase distributions of the generated left-handed circularly polarized (LCP) THz beams at 0.8, 1.0, 1.2, and 1.4 THz for case 6 and case 7, respectively. The scalebar in the top-left panel of Fig. 6f is applicable to all the results.
