The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
Markus B Raschke - One of the best experts on this subject based on the ideXlab platform.
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Optical Dielectric Function of silver
Physical Review B, 2015Co-Authors: Honghua U. Yang, Jeffrey D'archangel, Eric Tucker, M.l. Sundheimer, Glenn D. Boreman, Markus B RaschkeAbstract:In metal optics gold assumes a special status because of its practical importance in optoelectronic and nano-optical devices, and its role as a model system for the study of the elementary electronic excitations that underlie the interaction of electromagnetic fields with metals. However, largely inconsistent values for the frequency dependence of the Dielectric Function describing the optical response of gold are found in the literature. We performed precise spectroscopic ellipsometry measurements on evaporated gold, template-stripped gold, and single-crystal gold to determine the optical Dielectric Function across a broad spectral range from 300 nm to 25 μm (0.05-4.14 eV) with high spectral resolution. We fit the data to the Drude free-electron model, with an electron relaxation time ÏD=14±3 fs and plasma energy Ïp=8.45 eV. We find that the variation in Dielectric Functions for the different types of samples is small compared to the range of values reported in the literature. Our values, however, are comparable to the aggregate mean of the collection of previous measurements from over the past six decades. This suggests that although some variation can be attributed to surface morphology, the past measurements using different approaches seem to have been plagued more by systematic errors than previously assumed. © 2012 American Physical Society.
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optical Dielectric Function of gold
Physical Review B, 2012Co-Authors: Robert L Olmon, Brian Slovick, Timothy W. Johnson, Sang Hyun Oh, Glenn D. Boreman, D J Shelton, Markus B RaschkeAbstract:In metal optics gold assumes a special status because of its practical importance in optoelectronic and nano-optical devices, and its role as a model system for the study of the elementary electronic excitations that underlie the interaction of electromagnetic fields with metals. However, largely inconsistent values for the frequency dependence of the Dielectric Function describing the optical response of gold are found in the literature. We performed precise spectroscopic ellipsometry measurements on evaporated gold, template-stripped gold, and single-crystal gold to determine the optical Dielectric Function across a broad spectral range from 300 nm to 25 $\ensuremath{\mu}$m (0.05--4.14 eV) with high spectral resolution. We fit the data to the Drude free-electron model, with an electron relaxation time ${\ensuremath{\tau}}_{D}=14\ifmmode\pm\else\textpm\fi{}3$ fs and plasma energy $\ensuremath{\hbar}{\ensuremath{\omega}}_{p}=8.45$ eV. We find that the variation in Dielectric Functions for the different types of samples is small compared to the range of values reported in the literature. Our values, however, are comparable to the aggregate mean of the collection of previous measurements from over the past six decades. This suggests that although some variation can be attributed to surface morphology, the past measurements using different approaches seem to have been plagued more by systematic errors than previously assumed.
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Optical Dielectric Function of gold
Physical Review B - Condensed Matter and Materials Physics, 2012Co-Authors: Robert L Olmon, Brian Slovick, David Shelton, Timothy W. Johnson, Sang Hyun Oh, Glenn D. Boreman, Markus B RaschkeAbstract:In metal optics gold assumes a special status because of its practical importance in optoelectronic and nano-optical devices, and its role as a model system for the study of the elementary electronic excitations that underlie the interaction of electromagnetic fields with metals. However, largely inconsistent values for the frequency dependence of the Dielectric Function describing the optical response of gold are found in the literature. We performed precise spectroscopic ellipsometry measurements on evaporated gold, template-stripped gold, and single-crystal gold to determine the optical Dielectric Function across a broad spectral range from 300 nm to 25 μm (0.05-4.14 eV) with high spectral resolution. We fit the data to the Drude free-electron model, with an electron relaxation time ÏD=14±3 fs and plasma energy Ïp=8.45 eV. We find that the variation in Dielectric Functions for the different types of samples is small compared to the range of values reported in the literature. Our values, however, are comparable to the aggregate mean of the collection of previous measurements from over the past six decades. This suggests that although some variation can be attributed to surface morphology, the past measurements using different approaches seem to have been plagued more by systematic errors than previously assumed. © 2012 American Physical Society.
A Ng - One of the best experts on this subject based on the ideXlab platform.
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Dielectric Function of warm dense gold
Physics of Plasmas, 2008Co-Authors: Y Ping, D Hanson, I Koslow, Tadashi Ogitsu, David Prendergast, Eric Schwegler, Gilbert Collins, A NgAbstract:Single-state measurements of the broadband (450–800nm) Dielectric Function of gold using a supercontinuum probe are reviewed. These measurements have demonstrated the first evidence of the existence of band structure in ultrathin gold foils isochorically heated by a femtosecond laser pulse to energy densities of 106–107J∕kg. The Drude component of the Dielectric Function increases with energy density while the interband component shows both enhancement and redshift. Ab initio molecular-dynamics calculations based on thermalized electrons cannot reproduce the experimental results, suggesting a non-Fermi distribution of excited electrons.
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broadband Dielectric Function of nonequilibrium warm dense gold
Physical Review Letters, 2006Co-Authors: Y Ping, D Hanson, I Koslow, Tadashi Ogitsu, David Prendergast, Eric Schwegler, G W Collins, A NgAbstract:We report on the first single-state measurement of the broadband (450-800 nm) Dielectric Function of gold isochorically heated by a femtosecond laser pulse to energy densities of 10{sup 6}-10{sup 7} J/kg. A Drude and an inter-band component are clearly seen in the imaginary part of the Dielectric Function. The Drude component increases with energy density while the inter-band component shows both enhancement and red shift. This is in strong disagreement with predictions of a recent calculation of Dielectric Function based on limited k-point sampling.
J. Roy Sambles - One of the best experts on this subject based on the ideXlab platform.
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A surface plasmon study of the optical Dielectric Function of indium
Journal of Modern Optics, 2000Co-Authors: J. Roy Sambles, A. P. Hibbins, M. J. Jory, H. AzizbekyanAbstract:The optical Dielectric Function of indium is measured by optical excitation of surface plasmon polaritons on an indium- coated silica grating for a range of wavelengths in the visible region of the spectrum. By exciting the surface plasmon polariton at the buried indium-grating interface, the indium surface that supports the surface plasmon polariton is kept free from oxidation. Comparison of angle-dependent reflectivities with a grating modelling theory gives both the real and imaginary parts of the Dielectric Function of indium. These results are compared with free-electron models to obtain an estimate of the plasma frequency and relaxation time.
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Surface plasmon-polariton study of the optical Dielectric Function of titanium nitride
Journal of Modern Optics, 1998Co-Authors: A. P. Hibbins, J. Roy Sambles, C. R. LawrenceAbstract:Abstract This work presents the first detailed study of the optical Dielectric Function of optically thick TiN x films using grating coupling of radiation to surface plasmon-polaritons. Angle-dependent reflectivities are obtained in the wavelength range 500–875 nm and by comparison with grating modelling theory, we determine both the imaginary and the real parts of the Dielectric Function. This method provides an alternative to traditional characterization techniques (e.g. Kramers-Kronig analysis) that may require additional information about film thickness, or the sample's optical properties in other parts of the electromagnetic spectrum. We have fitted the determined Dielectric Function to a model based on a combination of interband absorptions and free-electron response evaluating both the plasma energy and the relaxation time.
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Surface plasmon-polariton study of the optical Dielectric Function of silver
Journal of Modern Optics, 1996Co-Authors: D. J. Nash, J. Roy SamblesAbstract:Abstract The optical Dielectric Function of silver is measured by excitation of surface plasmon-polaritons on a silver-covered silica grating for a range of wavelengths in the visible region of the spectrum. By exciting the surface plasmon-polariton at the grating/silver interface the silver is protected from sulphidization and contamination. Comparison of angle-dependent reflectivities with grating modelling theory gives both the real and imaginary parts of the Dielectric Function of the silver. The results compare very favourably with those obtained by other workers using more conventional methods for samples held in an ultra-high vacuum or with protected interfaces. Abstract The optical Dielectric Function of silver is measured by excitation of surface plasmon-polaritons on a silver-covered silica grating for a range of wavelengths in the visible region of the spectrum. By exciting the surface plasmon-polariton at the grating/silver interface the silver is protected from sulphidization and contamination. Comparison of angle-dependent reflectivities with grating modelling theory gives both the real and imaginary parts of the Dielectric Function of the silver. The results compare very favourably with those obtained by other workers using more conventional methods for samples held in an ultra-high vacuum or with protected interfaces.
Y Ping - One of the best experts on this subject based on the ideXlab platform.
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Dielectric Function of warm dense gold
Physics of Plasmas, 2008Co-Authors: Y Ping, D Hanson, I Koslow, Tadashi Ogitsu, David Prendergast, Eric Schwegler, Gilbert Collins, A NgAbstract:Single-state measurements of the broadband (450–800nm) Dielectric Function of gold using a supercontinuum probe are reviewed. These measurements have demonstrated the first evidence of the existence of band structure in ultrathin gold foils isochorically heated by a femtosecond laser pulse to energy densities of 106–107J∕kg. The Drude component of the Dielectric Function increases with energy density while the interband component shows both enhancement and redshift. Ab initio molecular-dynamics calculations based on thermalized electrons cannot reproduce the experimental results, suggesting a non-Fermi distribution of excited electrons.
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broadband Dielectric Function of nonequilibrium warm dense gold
Physical Review Letters, 2006Co-Authors: Y Ping, D Hanson, I Koslow, Tadashi Ogitsu, David Prendergast, Eric Schwegler, G W Collins, A NgAbstract:We report on the first single-state measurement of the broadband (450-800 nm) Dielectric Function of gold isochorically heated by a femtosecond laser pulse to energy densities of 10{sup 6}-10{sup 7} J/kg. A Drude and an inter-band component are clearly seen in the imaginary part of the Dielectric Function. The Drude component increases with energy density while the inter-band component shows both enhancement and red shift. This is in strong disagreement with predictions of a recent calculation of Dielectric Function based on limited k-point sampling.
Glenn D. Boreman - One of the best experts on this subject based on the ideXlab platform.
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Optical Dielectric Function of silver
Physical Review B, 2015Co-Authors: Honghua U. Yang, Jeffrey D'archangel, Eric Tucker, M.l. Sundheimer, Glenn D. Boreman, Markus B RaschkeAbstract:In metal optics gold assumes a special status because of its practical importance in optoelectronic and nano-optical devices, and its role as a model system for the study of the elementary electronic excitations that underlie the interaction of electromagnetic fields with metals. However, largely inconsistent values for the frequency dependence of the Dielectric Function describing the optical response of gold are found in the literature. We performed precise spectroscopic ellipsometry measurements on evaporated gold, template-stripped gold, and single-crystal gold to determine the optical Dielectric Function across a broad spectral range from 300 nm to 25 μm (0.05-4.14 eV) with high spectral resolution. We fit the data to the Drude free-electron model, with an electron relaxation time ÏD=14±3 fs and plasma energy Ïp=8.45 eV. We find that the variation in Dielectric Functions for the different types of samples is small compared to the range of values reported in the literature. Our values, however, are comparable to the aggregate mean of the collection of previous measurements from over the past six decades. This suggests that although some variation can be attributed to surface morphology, the past measurements using different approaches seem to have been plagued more by systematic errors than previously assumed. © 2012 American Physical Society.
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optical Dielectric Function of gold
Physical Review B, 2012Co-Authors: Robert L Olmon, Brian Slovick, Timothy W. Johnson, Sang Hyun Oh, Glenn D. Boreman, D J Shelton, Markus B RaschkeAbstract:In metal optics gold assumes a special status because of its practical importance in optoelectronic and nano-optical devices, and its role as a model system for the study of the elementary electronic excitations that underlie the interaction of electromagnetic fields with metals. However, largely inconsistent values for the frequency dependence of the Dielectric Function describing the optical response of gold are found in the literature. We performed precise spectroscopic ellipsometry measurements on evaporated gold, template-stripped gold, and single-crystal gold to determine the optical Dielectric Function across a broad spectral range from 300 nm to 25 $\ensuremath{\mu}$m (0.05--4.14 eV) with high spectral resolution. We fit the data to the Drude free-electron model, with an electron relaxation time ${\ensuremath{\tau}}_{D}=14\ifmmode\pm\else\textpm\fi{}3$ fs and plasma energy $\ensuremath{\hbar}{\ensuremath{\omega}}_{p}=8.45$ eV. We find that the variation in Dielectric Functions for the different types of samples is small compared to the range of values reported in the literature. Our values, however, are comparable to the aggregate mean of the collection of previous measurements from over the past six decades. This suggests that although some variation can be attributed to surface morphology, the past measurements using different approaches seem to have been plagued more by systematic errors than previously assumed.
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Optical Dielectric Function of gold
Physical Review B - Condensed Matter and Materials Physics, 2012Co-Authors: Robert L Olmon, Brian Slovick, David Shelton, Timothy W. Johnson, Sang Hyun Oh, Glenn D. Boreman, Markus B RaschkeAbstract:In metal optics gold assumes a special status because of its practical importance in optoelectronic and nano-optical devices, and its role as a model system for the study of the elementary electronic excitations that underlie the interaction of electromagnetic fields with metals. However, largely inconsistent values for the frequency dependence of the Dielectric Function describing the optical response of gold are found in the literature. We performed precise spectroscopic ellipsometry measurements on evaporated gold, template-stripped gold, and single-crystal gold to determine the optical Dielectric Function across a broad spectral range from 300 nm to 25 μm (0.05-4.14 eV) with high spectral resolution. We fit the data to the Drude free-electron model, with an electron relaxation time ÏD=14±3 fs and plasma energy Ïp=8.45 eV. We find that the variation in Dielectric Functions for the different types of samples is small compared to the range of values reported in the literature. Our values, however, are comparable to the aggregate mean of the collection of previous measurements from over the past six decades. This suggests that although some variation can be attributed to surface morphology, the past measurements using different approaches seem to have been plagued more by systematic errors than previously assumed. © 2012 American Physical Society.
