Near-fields

Similarly, the focusing capability of an array is the strongest focused beam which can be steered. The simplest way to evaluate it is to test a theoretical focusing time delay law, in the near-field and in the natural direction of propagation of the array. The beam pattern characteristics depth, lateral size and length of the focal spot must be found consistent with modelling and no lobe must appear above a predetermined level. [Pg.822]

Nie S and Emory S R 1997 Near-field surface-enhanced Raman spectroscopy on single silver nanoparticles Anal. Chem. 69 2631-5... [Pg.1228]

Smolyaninov I P, Zayats A V and Davis C C 1997 Near-field second-harmonic imaging of ferromagnetic and ferroelectric materials Opt. Lett. 22 1592-4... [Pg.1304]

B1.19.4 SCANNING NEAR-FIELD OPTICAL MICROSCOPY AND OTHER SPMS... [Pg.1715]

Of the methods described in this section, scaiming near-field optical microscopy (SNOM or NSOM) is tlie closest to being able to provide useful infonuation that is unobtainable by other means. Indeed, this teclmique has already been made available as a conunercial instmment. A detailed review of SNOM has been written by Pohl 11931. [Pg.1715]

Figure Bl.19.38. Schematic of a scaimmg near-field optical microscope (SNOM). (Taken from [196]. figure 2.)...

B1.19.4.2 SCANNING NEAR-FIELD ACOUSTIC MICROSCOPY (SNAM)... [Pg.1717]

This corresponds to the physician s stethoscope case mentioned above, and has been realized [208] by bringing one leg of a resonatmg 33 kHz quartz tiinmg fork close to the surface of a sample, which is being rastered in the x-y plane. As the fork-leg nears the sample, the fork s resonant frequency and therefore its amplitude is changed by interaction with the surface. Since the behaviour of the system appears to be dependent on the gas pressure, it may be assumed that the coupling is due to hydrodynamic mteractions within the fork-air-sample gap. Since the fork tip-sample distance is approximately 200 pm -1.120), tire teclmique is sensitive to the near-field component of the scattered acoustic signal. 1 pm lateral and 10 mn vertical resolutions have been obtained by the SNAM. [Pg.1717]

Pohl D W 1991 Soanning near-field optioal miorosoopy (SNOM) Advances/n Optical and Electron Microscopy yo 12, ed R Barer and V E Cosslett (London Aoademio)... [Pg.1729]

Durig U T, Pohl D W and Rohner F 1986 Near-field optical-scanning microscopy J. Appl. Phys. 59 3318 Pohl D W 1991 Scanning near-field optical microscopy (SNOM)/Icfr/. Opt. Electron. Microsc. 12 243... [Pg.1730]

Betzig E, Finn P L and Weiner J S 1992 Combined shear force and near-field scanning optical microscopy/4pp/. Phys. Lett. 60 2484... [Pg.1730]

Fischer U Ch, Durig U T and Pohl D W 1988 Near-field scanning microscopy in reflection Appl. Phys. Lett. 52 249 Cline J A, Barshatzky FI and Isaacson M 1991 Scanned-tip reflection-mode near-field scanning optical microscopy Ultramicroscopy 38 299... [Pg.1730]

Betzig E and Chichester R J 1993 Single molecules observed by near-field scanning optical microscopy Science 262 1422... [Pg.1730]

Trautman J K, Macklin J J, Brus L E and Betzig E 1994 Near-field spectroscopy of single molecules at room temperature Nature 369 40... [Pg.1730]

Smith D A, Webster S, Ayad M, Evans S D, Fogherty D and Batchelder D 1995 Development of a scanning near-field optical probe for localised Raman spectroscopy Ultramicroscopy 61 247... [Pg.1730]

Takahashi S, Futamata M and Ko]ima I 1999 Spectroscopy with scanning near-field optical microscopy using photon tunnelling mode J. Microscopy 194 519... [Pg.1730]

Zeisel D, Deckert V, Zenobi R and Vo-Dinh T 1998 Near-field surface-enhanced Raman spectroscopy of dye molecules adsorbed on silver island films Chem. Phys. Lett. 283 381... [Pg.1730]

Guenther P, Fischer U Ch and Dransfeld K 1989 Scanning near-field acoustic microscopy Appl. Phys. B 48 89 Williams C C and Wickramasinghe FI K 1986 Scanning thermal profiler App/. Phys. Lett. 49 1587... [Pg.1730]

One interesting new field in the area of optical spectroscopy is near-field scaiming optical microscopy, a teclmique that allows for the imaging of surfaces down to sub-micron resolution and for the detection and characterization of single molecules [, M]- Wlien applied to the study of surfaces, this approach is capable of identifying individual adsorbates, as in the case of oxazine molecules dispersed on a polymer film, illustrated in figure Bl.22,11 [82], Absorption and emission spectra of individual molecules can be obtamed with this teclmique as well, and time-dependent measurements can be used to follow the dynamics of surface processes. [Pg.1794]

Figure Bl.22.11. Near-field scanning optical microscopy fluorescence image of oxazine molecules dispersed on a PMMA film surface. Each protuberance in this three-dimensional plot corresponds to the detection of a single molecule, the different intensities of those features being due to different orientations of the molecules. Sub-diffraction resolution, in this case on the order of a fraction of a micron, can be achieved by the near-field scaiming arrangement. Spectroscopic characterization of each molecule is also possible. (Reprinted with pennission from [82]. Copyright 1996 American Chemical Society.)...

$Figure Bl.22.11. Near-field scanning optical microscopy fluorescence image of oxazine molecules dispersed on a PMMA film surface. Each protuberance in this three-dimensional plot corresponds to the detection of a single molecule, the different intensities of those features being due to different orientations of the molecules. Sub-diffraction resolution, in this case on the order of a fraction of a micron, can be achieved by the near-field scaiming arrangement. Spectroscopic characterization of each molecule is also possible. (Reprinted with pennission from [82]. Copyright 1996 American Chemical Society.)...$

A wide variety of measurements can now be made on single molecules, including electrical (e.g. scanning tunnelling microscopy), magnetic (e.g. spin resonance), force (e.g. atomic force microscopy), optical (e.g. near-field and far-field fluorescence microscopies) and hybrid teclmiques. This contribution addresses only Arose teclmiques tliat are at least partially optical. Single-particle electrical and force measurements are discussed in tire sections on scanning probe microscopies (B1.19) and surface forces apparatus (B1.20). [Pg.2483]

B) SPATIAL SELECTION WITH NEAR-FIELD OPTICS... [Pg.2487]

Figure Cl.5.3. Near-field fluorescence image 4.5 p.m square) of single oxazine 720 molecules dispersed on die surface of a PMMA film. Each peak (fwhm 100 nm) is due to a single molecule. The different intensities are due to different molecular orientations and spectra. Reprinted widi pennission from Xie 11221. Copyright 1996 American Chemical Society.

Figure Cl.5.4. Comparison of near-field and far-field fluorescence images, spectra and lifetimes for the same set of isolated single molecules of a carbocyanine dye at a PMMA-air interface. Note the much higher resolution of the near-field image. The spectmm and lifetime of the molecule indicated with the arrow were recorded with near-field excitation and with far-field excitation at two different excitation powers. Reproduced with pennission from Trautman and Macklin [125].

Betzig E and Trautman J K 1992 Near-field optios mieroseopy, speotrosoopy, and surfaee modifieation beyond the diffraetion limit Science 257 189-95... [Pg.2504]

Betzig E and Chiehester R J 1993 Single moleoules observed by near-field seanning optioal mieroseopy Science 262 1422-5... [Pg.2504]

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