Probing the negative permittivity perfect lens at optical frequencies using near-field optics and single molecule detection

Robert J Moerland,Niek F Van Hulst,Laurens Kuipers,Henkjan Gersen

doi:10.1364/opex.13.001604

Abstract

Recently, the existence of a perfect lens has been predicted, made of an artificial material that has a negative electric permittivity and a negative magnetic permeability. For optical frequencies a poormans version is predicted to exist in the sub-wavelength limit. Then, only the permittivity has to be negative, a demand that metals fulfill at optical frequencies. We propose a new measurement scheme to verify the performance of such a negative permittivity near-perfect lens at optical frequencies. The scheme is based on near-field scanning optical microscopy and single molecule detection. Prerequisite near-field single molecule data, necessary to assess the performance of the lens, is presented. A numerical evaluation, which includes absorption, of the expected performance of a slab of a realistic negative permittivity material confirms the merits of the scheme.

Highlights

Since the prediction of the existence of a perfect lens by Pendry in PRL [1], the scientific community has picked up the challenge to prove the expected focusing and amplification of evanescent electromagnetic waves by a slab of left handed material (LHM)
For optical frequencies a poormans version is predicted to exist in the sub-wavelength limit
We propose a new measurement scheme to verify the performance of such a negative permittivity near-perfect lens at optical frequencies

Summary

Introduction

Since the prediction of the existence of a perfect lens by Pendry in PRL [1], the scientific community has picked up the challenge to prove the expected focusing and amplification of evanescent electromagnetic waves by a slab of left handed material (LHM). Rather than being used for ‘perfect’ imaging purposes, the negative permittivity lens will find its use primarily in applications where sub-wavelength information in the form of evanescent waves is to be transferred and where only a discrete response is required, like in data storage and lithography. In these situations, the sensitivity of the lens to the polarization or, more useful in the near field, the actual Ex, Ey and Ez field components is less of an issue. The scheme is ideal for evaluating the imaging properties of the NPM lens

A direct near-field method

Expected performance of the near-field set-up

Conclusion