Figure 1

A space between a spherical surface and a planar surface (a) mapped onto a layer with planar boundaries (b). (c) Distribution of the radial, azimuthal, and axial (or vertical) diagonal components of permittivity and permeability given in Eq. (5) in the equivalent planar region (solid lines). Dashed lines show the same components in the equivalent planar region obtained for a tapered waveguide with radius-dependent refractive index, $n=\sqrt{\beta /\delta }$ (ideal cloak). (d) Normalized profile of the optimal waveguide shape plotted for a cloak radius of $b_0=172\mu \mathrm{m}$. The shape of the optimal waveguide may be approximated by a spherical surface placed on top of a flat surface, as shown by the dashed line.Reuse & Permissions

Figure 2

Tapered waveguide acting as an optical cloak (not to scale). (a) Cross-section sketch for the waveguide experiment. (b) 3D rendition of the experimental setup sketched in (a); in the figure one-quarter of the gold-coated lens is removed to show the interior details.Reuse & Permissions

Figure 3

(a) Microscope image of the waveguide without a particle (white light coming from the top). (b) Magnified Newton rings taken from the frame in (a). (c) Image of the waveguide with a gold particle (white light coming from the top). (d) Magnified Newton rings taken from the frame in (c). A long shadow cast by the gold particle upon coupling (via side illumination) 515-nm (e) and 488-nm (g) laser light into the waveguide. Magnified images of the rings for 515-nm (f) and 488-nm (h) light taken from frames in (e) and (g).Reuse & Permissions

Figure 4

Magnified images of the rings for (a) 488-nm and (b) 515-nm laser illumination. In both cases, no wire is placed in the waveguide.Reuse & Permissions