Subwavelength Imaging with Dielectric Metamaterial Solid-Immersion Lens

TL;DR

This paper presents a dielectric metamaterial solid-immersion lens (mSIL) that converts evanescent waves into far-field signals, enabling subwavelength imaging of 45-75 nm features with visible light.

Contribution

The work introduces a novel dielectric metamaterial lens that effectively transports evanescent waves, achieving super-resolution imaging with pure dielectric materials.

Findings

20% of evanescent wave energy directed into far-field

Resolved features as small as 45 nm under white light

Demonstrated super-resolution imaging with dielectric nanoparticles

Abstract

The limited resolution of a conventional optical microscope stems from the fact that the subwavelength information of an object is carried by evanescent waves, which exponentially decays in space and cannot reach the imaging plane. We introduce here a metamaterial solid immersion lens (mSIL), which utilizes closely-packed high-index nanoparticles as a composite media to effectively convert and transport evanescent waves from near-field to far-field. About 20% of evanescent wave energy of an ideal point source can be directed into far-field by mSIL. This has led to the exceptional imaging performance of mSIL in visible. Using 15 nm diameter TiO2 (n=2.55) nanoparticles as building block, we demonstrated that 45 nm -75 nm features can be resolved by the mSIL under a white light microscope. Our approach opens up the possibility to obtain a 'perfect lens' using pure dielectric materials.