toggle visibility Search & Display Options

Select All    Deselect All
 |   | 
Details
   print
  Records Links
Author Iomdina, E. N.; Seliverstov, S.; Sianosyan, A.; Teplyakova, K.; Rusova, A.; Goltsman, G. url  doi
openurl 
  Title The prospects of using the radiation for the assessment of corneal and scleral hydration Type Abstract
  Year 2016 Publication Acta Ophthalmol. Abbreviated Journal Acta Ophthalmol.  
  Volume (down) 94 Issue Pages  
  Keywords BWO, avalanche transit‐time diode, medicine, biology  
  Abstract Purpose

An adequate water balance (hydration extent) is one of the basic factors of normal eye function, including its external shells – the cornea and the sclera. THz systems creating images in reflected beams are likely to become ideal instruments of noninvasive testing of corneal and scleral hydration degree as THz radiation is highly sensitive to water content. The paper aims at studying the transmittance and reflectance spectra of the cornea and the sclera of rabbit and human eyes, as well as those of the whole rabbit eye, in the frequency range of 0.13–0.32 THz.

Methods

The experiments were carried out on 3 corneas and 3 rabbit scleras, 2 whole rabbit eyes, and 3 human healthy adult scleras using a specially developed THz system based on reliable and easy‐to‐use continuous wave sources: a backward‐wave oscillator and an avalanche transit‐time diode.

Results

The transmittance spectra of the cornea and the sclera and the dependence of the reflection coefficient of these tissues in THz range on water percentage content were determined. Comparison of the rabbit cornea hydrated from 73.2% to 76.3% concentration by mass demonstrated an approximately linear relationship between THz reflectivity and water concentration. The decrease of free water concentration by 1% leads to a drop of the reflectance coefficient by 13%. The parameters studied displayed noticeable differences between the sclera and the cornea of rabbits and between rabbit sclera and human sclera.

Conclusions

Preliminary results demonstrate that the proposed technique, based on continuous THz radiation, may be used to create a device for noninvasive testing of corneal and scleral hydration, which has good potential of wide‐scale practical application.

The work was supported by the Russian Foundation of Basic Research (grant No.15‐29‐03843)
 
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1755375X ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1333  
Permanent link to this record
 

 
Author Kardakova, A.; Shishkin, A.; Semenov, A.; Goltsman, G. N.; Ryabchun, S.; Klapwijk, T. M.; Bousquet, J.; Eon, D.; Sacépé, B.; Klein, T.; Bustarret, E. url  doi
openurl 
  Title Relaxation of the resistive superconducting state in boron-doped diamond films Type Journal Article
  Year 2016 Publication Phys. Rev. B Abbreviated Journal Phys. Rev. B  
  Volume (down) 93 Issue 6 Pages 064506  
  Keywords boron-doped diamond films, resistive superconducting state, relaxation time  
  Abstract We report a study of the relaxation time of the restoration of the resistive superconducting state in single crystalline boron-doped diamond using amplitude-modulated absorption of (sub-)THz radiation (AMAR). The films grown on an insulating diamond substrate have a low carrier density of about 2.5×1021cm−3 and a critical temperature of about 2K. By changing the modulation frequency we find a high-frequency rolloff which we associate with the characteristic time of energy relaxation between the electron and the phonon systems or the relaxation time for nonequilibrium superconductivity. Our main result is that the electron-phonon scattering time varies clearly as T−2, over the accessible temperature range of 1.7 to 2.2 K. In addition, we find, upon approaching the critical temperature Tc, evidence for an increasing relaxation time on both sides of Tc.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2469-9950 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1167  
Permanent link to this record
 

 
Author Vodolazov, D. Y.; Korneeva, Y. P.; Semenov, A. V.; Korneev, A. A.; Goltsman, G. N. url  doi
openurl 
  Title Vortex-assisted mechanism of photon counting in a superconducting nanowire single-photon detector revealed by external magnetic field Type Journal Article
  Year 2015 Publication Phys. Rev. B Abbreviated Journal Phys. Rev. B  
  Volume (down) 92 Issue 10 Pages 104503 (1 to 9)  
  Keywords SSPD, SNSPD  
  Abstract We use an external magnetic field to probe the detection mechanism of a superconducting nanowire single-photon detector. We argue that the hot belt model (which assumes partial suppression of the superconducting order parameter Δ across the whole width of the superconducting nanowire after absorption of the photon) does not explain observed weak-field dependence of the photon count rate (PCR) for photons with λ=450nm and noticeable decrease of PCR (with increasing the magnetic field) in a range of the currents for photons with wavelengths λ=450–1200nm. Found experimental results for all studied wavelengths can be explained by the vortex hot spot model (which assumes partial suppression of Δ in the area with size smaller than the width of the nanowire) if one takes into account nucleation and entrance of the vortices to the photon induced hot spot and their pinning by the hot spot with relatively large size and strongly suppressed Δ.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1098-0121 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1343  
Permanent link to this record
 

 
Author Zinoni, C.; Alloing, B.; Li, L. H.; Marsili, F.; Fiore, A.; Lunghi, L.; Gerardino, A.; Vakhtomin, Y. B.; Smirnov, K. V.; Gol’tsman, G. N. url  doi
openurl 
  Title Single-photon experiments at telecommunication wavelengths using nanowire superconducting detectors Type Journal Article
  Year 2007 Publication Appl. Phys. Lett. Abbreviated Journal Appl. Phys. Lett.  
  Volume (down) 91 Issue 3 Pages 031106 (1 to 3)  
  Keywords SSPD, SNSPD, APD  
  Abstract The authors report fiber-coupled superconducting single-photon detectors with specifications that exceed those of avalanche photodiodes, operating at telecommunication wavelength, in sensitivity, temporal resolution, and repetition frequency. The improved performance is demonstrated by measuring the intensity correlation function g(2)(τ) of single-photon states at 1300nm produced by single semiconductor quantum dots.

This work was supported by Swiss National Foundation through the “Professeur borsier” and NCCR Quantum Photonics program, FP6 STREP “SINPHONIA” (Contract No. NMP4-CT-2005-16433), IP “QAP” (Contract No. 15848), NOE “ePIXnet,” and the Italian MIUR-FIRB program.
 
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-6951 ISBN Medium  
  Area Expedition Conference  
  Notes Erratum: 1395 Approved no  
  Call Number Serial 1396  
Permanent link to this record
 

 
Author Ejrnaes, M.; Cristiano, R.; Quaranta, O.; Pagano, S.; Gaggero, A.; Mattioli, F.; Leoni, R.; Voronov, B.; Gol’tsman, G. url  doi
openurl 
  Title A cascade switching superconducting single photon detector Type Journal Article
  Year 2007 Publication Appl. Phys. Lett. Abbreviated Journal Appl. Phys. Lett.  
  Volume (down) 91 Issue 26 Pages 262509 (1 to 3)  
  Keywords SSPD, SNSPD, parallel-wire  
  Abstract We have realized superconducting single photon detectors with reduced inductance and increased signal pulse amplitude. The detectors are based on a parallel connection of ultrathin NbN nanowires with a common bias inductance. When properly biased, an absorbed photon induces a cascade switch of all the parallel wires generating a signal pulse amplitude of 2mV. The parallel wire configuration lowers the detector inductance and reduces the response time well below 1ns.

This work was performed in the framework of the EU project “SINPHONIA” NMP4-CT-2005-016433.
 
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-6951 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1418  
Permanent link to this record
Select All    Deselect All
 |   | 
Details
   print

Save Citations:
Export Records: