Technique to enhance the throughput on a near-field aperture by the use of self-focusing effect

Abstract

A technique to increase the throughput of a near-field aperture on a cantilever aperture is described. Using the self-focusing effect due to nonlinear optical Kerr effect in as-evaporated As2S3 glass, we found that the throughput of the near-field aperture with an aperture diameter ∼100 nm increases over 100 times compared with conventional tapered fiber tips. A theoretical qualitative analysis using the modified nonparaxial model to estimate the enhancement of the throughput is in good agreement with observed experimental results.