Experimental demonstration of optical cloaking of a free-standing Ag nanowire

We experimentally performed optical cloaking of a free-standing Ag nanowire fixed at the tip of a scanning tunneling microscope probe. The cloaking medium was a vacuum-evaporated molybdenum oxide (MoO₃) layer with a high refractive index (n∼2.2). This cloaking was designed such that light scattered by the cloaking target cancels out light scattered by the medium coating the target. The scattering light intensity was suppressed to 8% of that with no cloaking, indicating that the Ag nanowire was almost invisible. This is consistent with the theoretical prediction based on the Mie theory.