Guiding, focusing, and sensing on the subwavelength scale using metallic wire arrays.

We show that tapered arrays of thin metallic wires can manipulate electromagnetic fields on the subwavelength spatial scale. Two types of nanoscale imaging applications using terahertz and midinfrared waves are enabled: image magnification and radiation focusing. First, the tapered wire array acts as a multipixel TEM endoscope by capturing an electromagnetic field profile created by deeply subwavelength objects at the endoscope's tip and magnifying it for observation. Second, the image of a large mask at the endoscope's base is projected onto a much smaller image at the tip.