Subwavelength focusing by a micro/nanofiber array.

Utilizing the diffraction property of the output light from micro/nano fibers (MNFs), a new scheme based on a MNF array to focus optical beams with subwavelength resolution in the far field is proposed. By using the three-dimensional finite-difference beam-propagation method (FD-BPM), we investigated the diffraction interference effect of the MNFs during light propagation. The numerical stimulation demonstrates a focusing spot with FVHM of 0.43 lambda at a distance of 9 lambda from the output endface of MNF array. The effects of the characteristics of the array, the MNFs, and the input optical field on focusing are analyzed in detail. (C) 2009 Optical Society of America