Spatial aliasing based complementary meta-gratings for the high-efficient generation of different polarized multiple...

We demonstrate the synthesis of split dual circularly polarized (CP) beams with an additional linearly polarized (LP) radiation simultaneously from dual superposed birefringent meta-surface lenses formed of zebra crossing shaped meta-gratings. More specifically, each of the meta-surface lens is capable of generating birefringent CP refractions with different helicities and will readily achieve triple beams of different polarizations when a couple of left-hand CP (LHCP) and right-hand CP (RHCP) lobes radiating in the same direction. Polarization states of such triple-beam radiations can be specifically defined, and the vibrating electric field of each beam would thus be prescribed to form the LHCP and RHCP waves as well as a co- /cross-LP wave. Especially, we show that such a spatial aliasing of dual superposed birefringent meta-surface lenses will achieve promising aperture efficiencies for the multiple-beam generation on the basis of the complementary arrangement of different meta-gratings, and should thus pave the way for more advanced spatial-phase engineering with specific radiating characteristics using meta-surfaces.