Fig. 4

Experimental characterizations of the bi-channel meta-device I. As shined by LCP light at 1064 nm, a the LRM-recorded field pattern of the vortex SPP generated on the sample surface and b the CCD-captured field pattern as the vortex SPP interferes with a spherical wave. As shined by RCP light at 1064 nm, c the CCD-captured field pattern of the vortex beam reflected by the device and d the CCD-captured field pattern as the vortex beam interferes with a spherical wave