Subwavelength focusing of light by a tapered microtube

• DOI: 10.1063/1.3472224
• Publication Date: 2010-07-29T23:11:49Z
• Authors: Jian Fu; Hongtao Dong; Wei Fang
• Keywords: 0103 physical sciences; FOS: Physical sciences; 02 engineering and technology; 0210 nano-technology; 01 natural sciences; Physics - Optics; Optics (physics.optics)

We propose a mechanism for subwavelength focusing at optical frequencies based on the use of tapered microtube fabricated from glass capillary tube. Using coherent illumination 671 nm and near-field scanning microscope probe which was mounted three-axis piezonanopositioning stage, sequence two-dimensional intensity profiles were obtained. Our experimental results reveal smallest focal spot with near diffraction-limited full width half-maximum ∼435 (0.65λ) distance ∼1.47 μm (2.2λ) output end face microtube. The are in agreement our numerical simulation.