Reflection scanning near-field optical microscopy with uncoated fiber tips: How good is the resolution really?

Sandoghdar, Vahid; Wegscheider, S.; Krausch, Georg; Mlynek, J.

doi:10.1063/1.363957

Cited by 80 publications

(45 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Hence topographical artifacts cannot be excluded, see e.g. [16,17], and these images should not be taken for the quantitative estimation of the near-field optical resolution achieved. Such quantitative study will be performed after the preparation of plastic fiber probes with the subwavelength-size aperture for light transmission (actually the first aluminum-coated PMMA aperture probes have been successfully prepared and their testing is in progress).…”

Section: Resultsmentioning

confidence: 99%

Near-field scanning optical microscopy using polymethylmethacrylate optical fiber probes

Chibani¹,

Dukenbayev²,

Mensi³

et al. 2010

Ultramicroscopy

View full text Add to dashboard Cite

a b s t r a c tWe report the first use of polymethylmethacrylate (PMMA) optical fiber-made probes for scanning near-field optical microscopy (SNOM). The sharp tips were prepared by chemical etching of the fibers in ethyl acetate, and the probes were prepared by proper gluing of sharpened fibers onto the tuning fork in the conditions of the double resonance (working frequency of a tuning fork coincides with the resonance frequency of dithering of the free-standing part of the fiber) reported earlier for the case of glass fibers. Quality factors of the probes in the range 2000-6000 were obtained, which enables the realization of an excellent topographical resolution including state-of-art imaging of single DNA molecules. Near-field optical performance of the microscope is illustrated by the Photon Scanning Tunneling Microscope images of fluorescent beads with a diameter of 100 nm. The preparation of these plastic fiber probes proved to be easy, needs no hazardous material and/or procedures, and typical lifetime of a probe essentially exceeds that characteristic for the glass fiber probe.

show abstract

Section: Resultsmentioning

confidence: 99%

Near-field scanning optical microscopy using polymethylmethacrylate optical fiber probes

Chibani¹,

Dukenbayev²,

Mensi³

et al. 2010

Ultramicroscopy

View full text Add to dashboard Cite

show abstract

“…The phenomenon of increased near-field reflectivity was first described by Courjon et al 4 However, in contrast to the well established facts, an intriguing paper by Sandoghdar et al 5 claimed a decrease of the reflectivities upon shear-force approach due to interference effects and disputed the sudden discontinuity in the reflection signal as one approaches the tip to the sample. Unfortunately, that paper 5 confused the issue without providing relevant experimental details.…”

Section: Introductionmentioning

confidence: 96%

Scanning near-field optical microscopy by near-field reflectance enhancement: a versatile and valid technique

Kaupp

Herrmann

1999

J. Phys. Org. Chem.

View full text Add to dashboard Cite

The validity of reflection-back-to-the-fiber SNOM (scanning near-field optical microscopy) has been unduely questioned by an erratic approach curve that disputed the enhancement of near-field reflectance. It is shown now that only truncated (broken) tips without metal coating do not experience the enhancement when approached close to shear-force distance. However, sharp uncoated tips continue to show up the near-field enhancement, and chemical contrast on rough surfaces continues to be of basic value at submicroscopic resolution. It is pointed out how a good tip may be immediately differentiated from a broken one.

show abstract

“…The reasons for the apparent non-awareness might be the necessity of well defined although easily executed experimentation, and failure if these are not acknowledged [7]. Our technique requires sharp uncoated tips with high aspect ratio and rapid optical shear-force control to avoid tip breakage in fast scans.…”

Section: Introductionmentioning

confidence: 99%

“…Our technique requires sharp uncoated tips with high aspect ratio and rapid optical shear-force control to avoid tip breakage in fast scans. SNOM tips will however inevitably break if etched silica fibers (too blunt with large taper angles of 30°-50°) are used to scan on platinum (a material with exceptionally poor shear-force response) so that only artifacts arose that were rightfully withdrawn in [7] because of the undue experimentation. Importantly, the proper experimentation requires an intensity meter for uninterrupted check of the tip quality.…”

Section: Introductionmentioning

confidence: 99%

The Enhancement Effect at Local Reflectance and Emission Back to Apertureless SNOM Tips in the Shear-Force Gap

Kaupp¹

2011

TOSURSJ

View full text Add to dashboard Cite

Physical basics, technique, equipment, proper experimental conditions, and performance of apertureless reflection back-to-the-fiber SNOM (Rayleigh, Raman, fluorescence) under shear-force control are reported. This technique achieves optical resolutions of < 10 nm on flat surfaces and < 20 nm in the presence of topographies with very sharp tips (< 10 -20 nm end radius). It works due to the large enhancement of the reflection to very sharp tapered uncoated tips in the shear-force gap. The dependence of preset vibration damping is linear with variations between different chemical entities. Thus, the optical contrast appears as chemical contrast in reflection or emission. Such enhancement is however not obtained with blunt tips (> 30 nm end radius or broken). Typical images for all thinkable situations show that topographical artifacts are excluded and that, unlike conventional aperture SNOM, precise site coincidence of optical contrast and chemical variation (often traceable in the topography) is obtained on planes, hills, slopes, depressions, and hidden geodes, even on very rough surfaces that give, however, no optical contrast if they are chemically uniform. Furthermore, positive and negative contrast on hills, slopes, and depressions is featured within the same SNOM image each. Object sizes range from 30 nm in small scans to 25 m in 40 m wide scans. The versatile technique is therefore qualified for applications on real world samples without severe manipulations just as they occur in science, technique, and medicine. The principal differences of apertureless SNOM with collection in the shear-force gap and conventional SNOM are worked out.

show abstract

Reflection scanning near-field optical microscopy with uncoated fiber tips: How good is the resolution really?

Abstract: Simple fiber-optic confocal microscopy with nanoscale depth resolution beyond the diffraction barrier Rev. Sci. Instrum. 78, 093703 (2007);

Cited by 80 publications

References 15 publications

Near-field scanning optical microscopy using polymethylmethacrylate optical fiber probes

Near-field scanning optical microscopy using polymethylmethacrylate optical fiber probes

Scanning near-field optical microscopy by near-field reflectance enhancement: a versatile and valid technique

The Enhancement Effect at Local Reflectance and Emission Back to Apertureless SNOM Tips in the Shear-Force Gap

Contact Info

Product

Resources

About