Transmittance of subwavelength optical tunnel junctions

Photonic transfer through constrictions with subwavelength lateral size is at the origin of important nearfield optics developments. In this paper, we adapt the integral representation of Maxwell's equations to implement a realistic three-dimensional model of subwavelength optical constriction (SOC). We apply this scheme to investigate the optical properties of different SOC geometries. In particular, from the energy flow exiting the SOC we analyze the transmittance capability of such systems as a function of different external parameters. Preliminary steps toward the implementation of three-dimensional simulators of near-field microscopes are discussed. [S0163-1829(98)04439-7].