Superfocusing of surface polaritons in the conical structure

It is shown that at the propagation of a surface polariton through a pointed cone its wavelength decreases to zero as it approaches the edge of the cone. As a result, the polariton is focused in a very small region and the strengths of the wave fields anomalously increase. The phenomenon could be used for creation of a scanning near-field optical microscope to investigate the nanometer-scale surface areas. (C) 2000 American Institute of Physics. [S0021-8979(00)09805-4].