Near-field optical microscope based on local perturbation of a diffraction spot

Abstract

Using a vibrating opaque metallic tip, which periodically and locally modif ies the electromagnetic f ield distribution of a diffraction spot focused onto a sample surface through a microscope objective lens, we have observed optical resolution better than the diffraction limit both with topographical features and with purely optical ones. This procedure simultaneously generates a ref lection-mode near-field optical signal and a tapping-mode atomic force microscope signal and can therefore map independently the topography and the optical properties of a specimen.

Review of near-field optics and superlenses for sub-diffraction-limited nano-imaging

“…[95][96][97][98][99][100] Shortly after, researchers demonstrated similar apertureless SNOM systems that used a nanoscale tip probe instead of an aperture probe. [7][8][9][10][11][12][13][14] This type of microscope is often constructed from an AFM with a cantilever tip that is formed of either a dielectric, semiconductor, or metal. Apertureless SNOM quickly enabled resolutions down to the 1 nm scale.…”

“…[2][3][4][5][6] This resolution was extended further by apertureless SNOM systems, which employed a nanoscale scattering probe in the near-field instead of a subwavelength aperture. [7][8][9][10][11][12][13][14] At the turn of the new millennium, imaginative new approaches for controlling electromagnetic waves began to appear for imaging, [15][16][17][18][19][20][21][22][23] photovoltaics, [24][25][26] quantum information processing and simulations, [27][28][29][30][31] wireless communications, 32,33 and novel optical materials, [34][35][36][37][38][39][40] among many others. The advent of metamaterials with simultaneously negative permittivity and permeability 41 brought renewed interest in the properties of left-handed materials first proposed by Veselago,42 which Pendry demonstrated could be applied to sub-diffraction-limited imaging with his "perfect lens."…”

Controlling and tuning strong optical field gradients at a local probe microscope tip apex

“…In fact, this interaction does not only play a central role in apertureless SNOM, [1][2][3][4][5][6][7] but has also been implemented in local probe assisted nanoengineering, as for example in STM assisted nano-lithography. 8 A typical geometry for this problem is depicted in Fig.…”

Nanoscale optical imaging by atomic force infrared microscopy

“…Scattering near-field microscopy (SNIM) is based on the detection of scattered light from an oscillating antenna i.e. an AFM cantilever tip to enable optical imaging with high lateral resolution [19][20][21][22][23][24][25]. This method uses a vibrating metallic AFM cantilever tip, which periodically and locally modifies the electromagnetic field distribution of the excitation laser which has been focused to a diffraction limited spot size.…”