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Daniel F Sievenpiper - One of the best experts on this subject based on the ideXlab platform.

  • electron emission by long and short wavelength lasers essentials for the design of plasmonic photocathodes
    Journal of Applied Physics, 2018
    Co-Authors: Ebrahim Forati, Daniel F Sievenpiper
    Abstract:

    The theory of electron emission by metallic photocathodes under the exposure of long wavelength lasers will be studied. Photon energy in long wavelength lasers is less than the work function of the photocathode's material and can only emit electrons via tunneling through the potential barrier. The Optical Resonance effects (e.g., plasmonic Resonances) will be studied as an improvement to the performance of photocathodes. This paper is intended to provide self-sufficient materials to design Optical resonant surfaces (e.g., metasurfaces) for electron emission applications.The theory of electron emission by metallic photocathodes under the exposure of long wavelength lasers will be studied. Photon energy in long wavelength lasers is less than the work function of the photocathode's material and can only emit electrons via tunneling through the potential barrier. The Optical Resonance effects (e.g., plasmonic Resonances) will be studied as an improvement to the performance of photocathodes. This paper is intended to provide self-sufficient materials to design Optical resonant surfaces (e.g., metasurfaces) for electron emission applications.

  • electron emission by long and short wavelength lasers essentials for the design of plasmonic photocathodes
    arXiv: Applied Physics, 2018
    Co-Authors: Ebrahim Forati, Daniel F Sievenpiper
    Abstract:

    Theory of electron emission by metallic photocathodes under the exposure of long wavelength lasers will be studied. Energy of photons in long wavelength lasers is less than the work function of the photocathode material, and can only emit electrons via tunneling through the potential barrier. The Optical Resonance effect (e.g. plasmonic Resonances) will be studied as an improvement to the performance of photocathodes. This paper is intended to provide self-sufficient materials to design Optical resonant surfaces (e.g. metasurfaces) for electron emission applications.

Jeffrey J. L. Carson - One of the best experts on this subject based on the ideXlab platform.

  • effect of surface plasmon energy matching on the sensing capability of metallic nano hole arrays
    Applied Physics Letters, 2012
    Co-Authors: Mohamadreza Najiminaini, Fartash Vasefi, Bozena Kaminska, Jeffrey J. L. Carson
    Abstract:

    We report on a nano-hole array structure with a single cavity beneath the perforated gold film. Structures were fabricated with a variety of cavity depths. The Optical Resonance of each structure as well as the surface plasmon (SP) energy matching between the top and bottom of the gold film were investigated. We also experimentally evaluated the sensitivity of the structures as surface plasmon Resonance (SPR) sensors. We observed a 1.6-fold enhancement in bulk SPR sensitivity and a 3-fold improvement in figure of merit for a structure with a 350-nm cavity depth compared to a structure with a 5-nm cavity depth.We report on a nano-hole array structure with a single cavity beneath the perforated gold film. Structures were fabricated with a variety of cavity depths. The Optical Resonance of each structure as well as the surface plasmon (SP) energy matching between the top and bottom of the gold film were investigated. We also experimentally evaluated the sensitivity of the structures as surface plasmon Resonance (SPR) sensors. We observed a 1.6-fold enhancement in bulk SPR sensitivity and a 3-fold improvement in figure of merit for a structure with a 350-nm cavity depth compared to a structure with a 5-nm cavity depth.

  • Optical Resonance transmission properties of nano-hole arrays in a gold film: effect of adhesion layer.
    Optics express, 2011
    Co-Authors: Mohamadreza Najiminaini, Fartash Vasefi, Bozena Kaminska, Jeffrey J. L. Carson
    Abstract:

    In this paper, we present a systematic study on the influence of composition of the adhesion layer between gold and a Pyrex substrate on the Optical Resonance transmission properties of nano-hole arrays in an Optically thick gold film. Large nano-hole arrays with different hole periodicities in a square lattice arrangement were fabricated using Electron Beam Lithography using different adhesion layers (chromium, titanium, or etched adhesion layer). The fabricated nano-hole arrays were Optically characterized using transmission spectroscopy. The Optical performance of each nano-hole array was numerically simulated using a Finite Difference Time Domain (FDTD) method. The experiments and simulations revealed that the Optical Resonance transmission properties (i.e. the Resonance wavelength, the spectral transmission modulation ratio, and the Resonance bandwidth) of the nano-hole arrays depended highly on the composition and the thickness of the adhesion layer. The Optical Resonance bandwidths were larger for the nano-hole arrays with chromium or titanium adhesion layers. Also, a red-shift of the Optical Resonance peak was observed for nano-hole arrays with a metal adhesion layer compared to the corresponding nano-hole arrays with an etched adhesion layer, but the red-shift was greatest for the nano-hole array with the titanium adhesion layer. For adhesion layers of greater thickness, the Optical Resonance peaks were reduced in magnitude. Finally, nano-hole arrays with an etched adhesion layer had a significant blue-shift in the Optical Resonance peak and a narrower Optical Resonance bandwidth compared to nano-hole arrays with a titanium or a chromium adhesion layer. Consequently, a narrow Optical Resonance bandwidth characteristic of a nano-hole array with an etched adhesion layer can potentially enhance the spectral selectivity and offer improved Optical performance.

  • Experimental analysis of Optical Resonance transmission properties of sub-wavelength hole arrays in Optically thick metal films
    Plasmonics in Biology and Medicine VIII, 2011
    Co-Authors: Mohamadreza Najiminaini, Fartash Vasefi, Bozena Kaminska, Jeffrey J. L. Carson
    Abstract:

    In this paper, we present detailed experimental analysis on the Optical Resonance transmission properties of nano-hole arrays in metallic films. Arrays of sub-wavelength holes with different periodicity (spacing between adjacent holes) in a square lattice arrangement were fabricated in Optically thick metal films (Au, Ag, and Al) on a Pyrex substrate using Electron Beam Lithography. The Optical transmission spectra of the nano-hole arrays were characterized in the visible and near infrared regime. The Optical Resonance transmission properties were observed to depend on the type of metal film and the periodicity in the lattice arrangement.

  • Effect of adhesion layer on Optical Resonance transmission properties of nano-hole arrays in an Optically thick gold film
    Plasmonics in Biology and Medicine VIII, 2011
    Co-Authors: Mohamadreza Najiminaini, Fartash Vasefi, Bozena Kaminska, Jeffrey J. L. Carson
    Abstract:

    In this paper, we present experimental analysis on the effect of composition of the adhesion layer (chromium or titanium) between gold and a Pyrex substrate on the Optical Resonance transmission properties of nano-hole arrays in an Optically thick gold film. Nano-hole arrays of different hole periodicities in a square lattice arrangement were fabricated with three types of adhesion layer (5 nm Cr, 5 nm Ti or 10 nm Ti). The Optical transmission of each nano-hole array was measured and the Optical Resonance transmission properties were analyzed and compared as a function of hole periodicity and type of adhesion layer.

  • Experimental and numerical analysis on the Optical Resonance transmission properties of nano-hole arrays
    Optics express, 2010
    Co-Authors: Mohamadreza Najiminaini, Fartash Vasefi, Bozena Kaminska, Jeffrey J. L. Carson
    Abstract:

    In this paper, we present experimental and numerical analysis on Extraordinary Optical Transmission (EOT) or Optical Resonance transmission through various nano-hole arrays constructed from an Optically thick metal film within the visible and near infra-red spectrum. Nano-hole arrays with different geometrical parameters (hole size, hole shape, and hole periodicity) having their EOT properties in the visible and near-infrared regime were simulated based on Finite Difference Time Domain (FDTD). Large nano-hole arrays with geometric properties similar to the simulated arrays were fabricated using Electron Beam Lithography (EBL). The Optical Resonance transmission properties (Resonance position, transmission efficiency, and spectral bandwidth of Resonance peak) of the fabricated nano-hole arrays were characterized. Finally, the experimental and numerical results were analyzed to determine the dependencies and discrepancies between Optical Resonance transmission properties for various nano-hole arrays.

Ebrahim Forati - One of the best experts on this subject based on the ideXlab platform.

  • electron emission by long and short wavelength lasers essentials for the design of plasmonic photocathodes
    Journal of Applied Physics, 2018
    Co-Authors: Ebrahim Forati, Daniel F Sievenpiper
    Abstract:

    The theory of electron emission by metallic photocathodes under the exposure of long wavelength lasers will be studied. Photon energy in long wavelength lasers is less than the work function of the photocathode's material and can only emit electrons via tunneling through the potential barrier. The Optical Resonance effects (e.g., plasmonic Resonances) will be studied as an improvement to the performance of photocathodes. This paper is intended to provide self-sufficient materials to design Optical resonant surfaces (e.g., metasurfaces) for electron emission applications.The theory of electron emission by metallic photocathodes under the exposure of long wavelength lasers will be studied. Photon energy in long wavelength lasers is less than the work function of the photocathode's material and can only emit electrons via tunneling through the potential barrier. The Optical Resonance effects (e.g., plasmonic Resonances) will be studied as an improvement to the performance of photocathodes. This paper is intended to provide self-sufficient materials to design Optical resonant surfaces (e.g., metasurfaces) for electron emission applications.

  • electron emission by long and short wavelength lasers essentials for the design of plasmonic photocathodes
    arXiv: Applied Physics, 2018
    Co-Authors: Ebrahim Forati, Daniel F Sievenpiper
    Abstract:

    Theory of electron emission by metallic photocathodes under the exposure of long wavelength lasers will be studied. Energy of photons in long wavelength lasers is less than the work function of the photocathode material, and can only emit electrons via tunneling through the potential barrier. The Optical Resonance effect (e.g. plasmonic Resonances) will be studied as an improvement to the performance of photocathodes. This paper is intended to provide self-sufficient materials to design Optical resonant surfaces (e.g. metasurfaces) for electron emission applications.

H. Saito - One of the best experts on this subject based on the ideXlab platform.

  • Pulse broadening in a Ne–CuBr–Zn laser system by Optical Resonance pumping
    Applied Physics Letters, 2002
    Co-Authors: K. Fujii, K. Uno, F. Tawada, T. Hishida, M. Nishizawa, M. Suzuki, K. Oouchi, R. Tsuji, H. Saito
    Abstract:

    A Zn atom is employed as the light source for Optical Resonance pumping to a high lying energy level of the Cu atom, thereby depopulating both the Cu lower laser level and enhancing the upper laser level via cascading decays that is carried out simultaneously. The width of the lasing pulse broadened by 220% and the peak value increased by 180%. The cascading decay route was clarified by observing the fluorescence lines, λ=675.1, 793.5, and 809.0 nm, thereby specifying five levels of excitation loop.

  • pulse broadening in a ne cubr zn laser system by Optical Resonance pumping
    Applied Physics Letters, 2002
    Co-Authors: K. Fujii, K. Uno, F. Tawada, T. Hishida, M. Nishizawa, M. Suzuki, K. Oouchi, R. Tsuji, H. Saito
    Abstract:

    A Zn atom is employed as the light source for Optical Resonance pumping to a high lying energy level of the Cu atom, thereby depopulating both the Cu lower laser level and enhancing the upper laser level via cascading decays that is carried out simultaneously. The width of the lasing pulse broadened by 220% and the peak value increased by 180%. The cascading decay route was clarified by observing the fluorescence lines, λ=675.1, 793.5, and 809.0 nm, thereby specifying five levels of excitation loop.

Mohamadreza Najiminaini - One of the best experts on this subject based on the ideXlab platform.

  • effect of surface plasmon energy matching on the sensing capability of metallic nano hole arrays
    Applied Physics Letters, 2012
    Co-Authors: Mohamadreza Najiminaini, Fartash Vasefi, Bozena Kaminska, Jeffrey J. L. Carson
    Abstract:

    We report on a nano-hole array structure with a single cavity beneath the perforated gold film. Structures were fabricated with a variety of cavity depths. The Optical Resonance of each structure as well as the surface plasmon (SP) energy matching between the top and bottom of the gold film were investigated. We also experimentally evaluated the sensitivity of the structures as surface plasmon Resonance (SPR) sensors. We observed a 1.6-fold enhancement in bulk SPR sensitivity and a 3-fold improvement in figure of merit for a structure with a 350-nm cavity depth compared to a structure with a 5-nm cavity depth.We report on a nano-hole array structure with a single cavity beneath the perforated gold film. Structures were fabricated with a variety of cavity depths. The Optical Resonance of each structure as well as the surface plasmon (SP) energy matching between the top and bottom of the gold film were investigated. We also experimentally evaluated the sensitivity of the structures as surface plasmon Resonance (SPR) sensors. We observed a 1.6-fold enhancement in bulk SPR sensitivity and a 3-fold improvement in figure of merit for a structure with a 350-nm cavity depth compared to a structure with a 5-nm cavity depth.

  • Optical Resonance transmission properties of nano-hole arrays in a gold film: effect of adhesion layer.
    Optics express, 2011
    Co-Authors: Mohamadreza Najiminaini, Fartash Vasefi, Bozena Kaminska, Jeffrey J. L. Carson
    Abstract:

    In this paper, we present a systematic study on the influence of composition of the adhesion layer between gold and a Pyrex substrate on the Optical Resonance transmission properties of nano-hole arrays in an Optically thick gold film. Large nano-hole arrays with different hole periodicities in a square lattice arrangement were fabricated using Electron Beam Lithography using different adhesion layers (chromium, titanium, or etched adhesion layer). The fabricated nano-hole arrays were Optically characterized using transmission spectroscopy. The Optical performance of each nano-hole array was numerically simulated using a Finite Difference Time Domain (FDTD) method. The experiments and simulations revealed that the Optical Resonance transmission properties (i.e. the Resonance wavelength, the spectral transmission modulation ratio, and the Resonance bandwidth) of the nano-hole arrays depended highly on the composition and the thickness of the adhesion layer. The Optical Resonance bandwidths were larger for the nano-hole arrays with chromium or titanium adhesion layers. Also, a red-shift of the Optical Resonance peak was observed for nano-hole arrays with a metal adhesion layer compared to the corresponding nano-hole arrays with an etched adhesion layer, but the red-shift was greatest for the nano-hole array with the titanium adhesion layer. For adhesion layers of greater thickness, the Optical Resonance peaks were reduced in magnitude. Finally, nano-hole arrays with an etched adhesion layer had a significant blue-shift in the Optical Resonance peak and a narrower Optical Resonance bandwidth compared to nano-hole arrays with a titanium or a chromium adhesion layer. Consequently, a narrow Optical Resonance bandwidth characteristic of a nano-hole array with an etched adhesion layer can potentially enhance the spectral selectivity and offer improved Optical performance.

  • Experimental analysis of Optical Resonance transmission properties of sub-wavelength hole arrays in Optically thick metal films
    Plasmonics in Biology and Medicine VIII, 2011
    Co-Authors: Mohamadreza Najiminaini, Fartash Vasefi, Bozena Kaminska, Jeffrey J. L. Carson
    Abstract:

    In this paper, we present detailed experimental analysis on the Optical Resonance transmission properties of nano-hole arrays in metallic films. Arrays of sub-wavelength holes with different periodicity (spacing between adjacent holes) in a square lattice arrangement were fabricated in Optically thick metal films (Au, Ag, and Al) on a Pyrex substrate using Electron Beam Lithography. The Optical transmission spectra of the nano-hole arrays were characterized in the visible and near infrared regime. The Optical Resonance transmission properties were observed to depend on the type of metal film and the periodicity in the lattice arrangement.

  • Effect of adhesion layer on Optical Resonance transmission properties of nano-hole arrays in an Optically thick gold film
    Plasmonics in Biology and Medicine VIII, 2011
    Co-Authors: Mohamadreza Najiminaini, Fartash Vasefi, Bozena Kaminska, Jeffrey J. L. Carson
    Abstract:

    In this paper, we present experimental analysis on the effect of composition of the adhesion layer (chromium or titanium) between gold and a Pyrex substrate on the Optical Resonance transmission properties of nano-hole arrays in an Optically thick gold film. Nano-hole arrays of different hole periodicities in a square lattice arrangement were fabricated with three types of adhesion layer (5 nm Cr, 5 nm Ti or 10 nm Ti). The Optical transmission of each nano-hole array was measured and the Optical Resonance transmission properties were analyzed and compared as a function of hole periodicity and type of adhesion layer.

  • Experimental and numerical analysis on the Optical Resonance transmission properties of nano-hole arrays
    Optics express, 2010
    Co-Authors: Mohamadreza Najiminaini, Fartash Vasefi, Bozena Kaminska, Jeffrey J. L. Carson
    Abstract:

    In this paper, we present experimental and numerical analysis on Extraordinary Optical Transmission (EOT) or Optical Resonance transmission through various nano-hole arrays constructed from an Optically thick metal film within the visible and near infra-red spectrum. Nano-hole arrays with different geometrical parameters (hole size, hole shape, and hole periodicity) having their EOT properties in the visible and near-infrared regime were simulated based on Finite Difference Time Domain (FDTD). Large nano-hole arrays with geometric properties similar to the simulated arrays were fabricated using Electron Beam Lithography (EBL). The Optical Resonance transmission properties (Resonance position, transmission efficiency, and spectral bandwidth of Resonance peak) of the fabricated nano-hole arrays were characterized. Finally, the experimental and numerical results were analyzed to determine the dependencies and discrepancies between Optical Resonance transmission properties for various nano-hole arrays.