Local electric field enhancement near arrays of polarizable cylindrical tubes

Abstract

We present a multipolar formalism for the local field near an arbitrary array of parallel inhomogeneous cylinders in the long wavelength limit. For very thin tubes the fields may be expressed as a superposition of normal modes. The formalism is applied to arrays of parallel carbon shells filled with silver. A strong enhancement is obtained near the surface plasmon resonance of silver, while that at the resonance of graphite is rather weak. The Raman signal of molecules placed at sites of high field may be enhanced by up to eight orders of magnitude.