Object distance-independent near-field subwavelength imaging of metal waveguide arrays

Abstract

A prism-shape microlens constructed with two-dimensional nanoscale metal waveguide arrays (MWGAs) is introduced for near-field subwavelength imaging. Finite-difference time-domain numerical simulations reveal that the microlens shows interesting object distance-independent subwavelength imaging as the object distance ranges from 100 nm to 1000 nm and the concave angle of the prism-shape lens is less than 150°. The possibility of using such microlens for array microimaging is also demonstrated. The microlens may provide potential applications in nanophotonics, lithography, and superresolution imaging.