Biomedical subjects

I I Smolyaninov

Publications and source records attributed to I I Smolyaninov.

7 recordsLinked to original sources

PubMed2006

High-optical-throughput individual nanoscale aperture in a multilayered metallic film.

The optical transmission of an individual subwavelength aperture in a multilayered metal film is shown to be enhanced compared with that of a homogeneous metal film. The enhancement effect is due to the light coupling to surface plasmon excitation facilitated by a film periodicity. The sensitivity of the transmission to the dielectric filling of the aperture is also shown. The latter effect can be used to switch and control the transmittance. Devices based on enhanced transmission through nanosized apertures can find applications in high-density optical and magneto-optical data storage, high-resolution microscopy, and photolithography, where nanoscale light sources with high-optical-power throughput are required, as well as in sensor applications.

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PubMed2002

Single-photon tunneling via localized surface plasmons.

Strong evidence of a single-photon tunneling effect, a direct analog of single-electron tunneling, has been obtained in the measurements of light tunneling through individual subwavelength pinholes in a gold film covered with a layer of polydiacetylene. The transmission of some pinholes reached saturation because of the optical nonlinearity of polydiacetylene at a very low light intensity of a few thousand photons per second. This result is explained theoretically in terms of a "photon blockade," similar to the Coulomb blockade phenomenon observed in single-electron tunneling experiments. Single-photon tunneling may find applications in the fields of quantum communication and information processing.

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PubMed2001

High resolution study of permanent photoinduced reflectivity changes and charge-order domain switching in Bi(0.3)Ca(0.7)MnO(3).

We report near-field and far-field optical microscopic studies of photoinduced effects in charge-ordered Bi(0.3)Ca(0.7)MnO(3). Unlike previously reported transient photoinduced effects in manganites, we have observed permanent reflectivity changes following local sample illumination with 488 nm light. High-resolution images of exposed regions reveal optical contrast on a submicrometer scale. This observation indicates that photonic band-gap structures may be created using holographic recording in manganites. We also present images of photoinduced charge-order domain switching in Bi(0.3)Ca(0.7)MnO(3).

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PubMed2001

Near-field second harmonic imaging of the c/a/c/a polydomain structure of epitaxial PbZrxTi(1-x)O3 thin films.

Near-field optical second harmonic microscopy has been applied to imaging of the c/a/c/a polydomain structure of epitaxial PbZrxTi1-xO3 thin films in the 0 < x < 0.4 range. Comparison of the near-field optical images and the results of atomic force microscopy and X-ray diffraction studies show that an optical resolution of the order of 100 nm is achieved. Symmetry properties of the near-field second harmonic signal allow us to obtain good optical contrast between the local second harmonic generation in c- and a-domains. Experimentally measured near-field second harmonic images have been compared with the results of theoretical calculations. Good agreement between theory and experiment is demonstrated.

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PubMed2000

Supercooling molecular hydrogen down through the superfluid transition.

Recent calculations by Vorobev and Malyshenko [JETP Lett. 71, 39 (2000)] show that molecular hydrogen may stay liquid and superfluid in strong electric fields of the order of 4x10(7) V/cm. I demonstrate that strong local electric fields of similar magnitude exist beneath a two-dimensional layer of electrons localized in the image potential above the surface of solid hydrogen. Even stronger local fields exist around charged particles (ions or electrons) if the surface or bulk of a solid hydrogen crystal is statically charged. Measurements of the frequency shift of the 1 --> 2 photoresonance transition in the spectrum of a two-dimensional layer of electrons above a positively or negatively charged solid hydrogen surface performed in the temperature range 7-13.8 K support the prediction of electric field induced surface melting. The range of surface charge density necessary to stabilize the liquid phase of molecular hydrogen at the temperature of superfluid transition is estimated.

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PubMedDate not supplied

Near-field second harmonic imaging of lead zirconate titanate piezoceramic.

Near-field optical microscopy has been used to image variations in local optical second harmonic generation (SHG) from the surface of lead zirconate titanate (PZT) piezoceramic. As PZT ceramic is a strongly scattering medium. SHG occurs in the thin layer near the surface of the ceramic. Thus, individual crystalline grains and grain boundaries located near the surface are the main features visible in the images. In general, this technique allows us to determine the local poling direction of individual submicrometre-sized crystalline grains of ceramic by near-field SH imaging at different angles of incidence and polarization states of the fundamental excitation light. In some cases 'hot spots' of submicrometre size showing enhanced SHG have been observed. This enhancement is believed to result from local cavity resonances.

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PubMedDate not supplied

Near-field imaging of surface-enhanced second harmonic generation.

Surface-enhanced second harmonic generation from individual topographical defects of an otherwise flat gold film and from metal-coated diffraction gratings was measured using a near-field optical microscope. Experimentally measured second harmonic field distributions were compared with theoretical calculations.

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