Modified Debye model parameters of metals applicable for broadband calculations

Gai, Hongfeng; Wang, Jia; Tian, Qi

doi:10.1364/ao.46.002229

Cited by 149 publications

(74 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The incident NIR pulses were assumed to have a temporal duration of 10 fs with a 100 nm spectral width centred at a wavelength of 800 nm. The wavelength-dependent dielectric constant of the waveguide material (silver) was estimated by means of a modified Debye model 28 .…”

Section: Methodsmentioning

confidence: 99%

Plasmonic generation of ultrashort extreme-ultraviolet light pulses

et al. 2011

View full text Add to dashboard Cite

Ultrashort extreme-ultraviolet pulses are a key tool in timeresolved spectroscopy for the investigation of electronic motion in atoms 1,2 , molecules 3 and solids 4 . High-harmonic generation is a well-established process for producing ultrashort extreme-ultraviolet pulses by direct frequency upconversion of femtosecond near-infrared pulses [5][6][7] . However, elaborate pump-probe experiments performed on the attosecond timescale 8,9 require continuous efforts to improve the spatiotemporal coherence and also the repetition rate of the generated pulses. Here, we demonstrate a three-dimensional metallic waveguide for the plasmonic generation of ultrashort extreme-ultraviolet pulses by means of field enhancement using surface-plasmon polaritons. The intensity enhancement factor reaches a peak of ∼350, allowing generation up to the 43rd harmonic in xenon gas, with a modest incident intensity of ∼1 3 10 11 W cm -2 . The pulse repetition rate is maintained as high as 75 MHz without external cavities. The plasmonic waveguide is fabricated on a cantilever microstructure and is therefore suitable for near-field spectroscopy with nanometre-scale lateral selectivity.Surface-plasmon polaritons (SPPs) are described as the electromagnetic wave propagating along a metal-dielectric interface that results from coupling between incident photons and surface plasmons 10,11 . In nanostructured tapered waveguides, SPPs can be controlled to adiabatically follow the geometric shape of the waveguide and asymptotically stop at the tip of the taper where the local crosssectional dimension becomes infinitesimally small 12,13 . As a result, SPPs can be focused beyond the diffraction limit in three dimensions on a sub-wavelength spot, with drastically enhanced optical intensity [12][13][14] . The effect of SPP adiabatic nanofocusing has been confirmed, studied and also tested for nanometre-scale microscopy in a series of earlier experiments [15][16][17][18][19] .In our investigation, this intriguing phenomenon of SPP adiabatic nanofocusing is used to generate ultrashort extreme ultraviolet (EUV) pulses directly from near-infrared (NIR) pulses. As depicted in Fig. 1, a three-dimensional waveguide was devised to concentrate the incident NIR pulses into a sub-wavelength spot, allowing highharmonic generation of EUV light pulses to take place with high spatiotemporal coherence. The waveguide is a metallic nanostructure made of silver and has a hollow hole that takes the shape of a tapered cone with its elliptical cross-section decreasing from the inlet aperture (minor-axis diameter, 2 mm) to the exit aperture (minor-axis diameter, 100 nm). The incident NIR pulses are focused on the inlet aperture at a repetition rate of 75 MHz with a moderate intensity of 1 × 10 11 W cm 22 . While each NIR pulse propagates through the tapered hole towards the exit aperture, the electric field intensity inside the hole undergoes a substantial boost that is sustained by the SPPs driven by the incident NIR pulse. Consequently, high-harmonic EUV pulses are generate...

show abstract

Section: Methodsmentioning

confidence: 99%

Plasmonic generation of ultrashort extreme-ultraviolet light pulses

et al. 2011

View full text Add to dashboard Cite

show abstract

“…The boundary conditions are the perfect matching layers, which would completely absorb TM waves that are encountering the boundaries. The complex relative permittivity of silver is characterized by the modified Debye model [22], "ðwÞ ¼ " 1 þ ð" s À " 1 Þ=ð1 þ iwtÞ þ s=iw" 0 , where ε ∞ = 3.8344 is the infinite frequency permittivity, ε s =−9530.5 is the static permittivity, C=7.35×10 −15 s is the relaxation time, and σ=1.1486×10 −7 s/m is the conductivity.…”

Section: Structure and Computational Methodsmentioning

confidence: 99%

Numerical Investigation of a Branch-Shaped Filter Based on Metal-Insulator-Metal Waveguide

et al. 2011

View full text Add to dashboard Cite

Using the finite difference time-domain method, we present a comprehensive numerical investigation of a branch-shaped filter based on the metal-insulator-metal (MIM) waveguide. The results show that several passbands and stopbands appear in the transmission spectra, which are resulted by the phase differences between the surface plasmon polaritons (SPPs) propagating along the straight waveguide and the SPPs resonating in the circuit formed by the branch and the straight waveguide. The effects of the structural parameters of the branch-shaped filters on their transmission properties are also studied. These results not only present an alternative plasmonic filter for the MIM waveguides but also help us to understand the transmission properties of the circuit-shaped structures.

show abstract

“…The FDTD method is the most popular method to analyze the optical properties of the nanoparticles [11][12][13][14][15][16][17][18][19][20][21][22][23] and a homemade FDTD program is used in the simulations. The method is an explicit timemarching algorithm used to solve Maxwell's curl equations on a Optics Communications 283 (2010) 2947-2952 discredited spatial grid termed as the "Yee cell" [22,23].…”

Section: Fdtd Modeling Methodsmentioning

confidence: 99%

“…The method is an explicit timemarching algorithm used to solve Maxwell's curl equations on a Optics Communications 283 (2010) 2947-2952 discredited spatial grid termed as the "Yee cell" [22,23]. In order to model the dispersive metal material, the modified Debye model for the frequency-dependent permittivity function is used [21].…”

Section: Fdtd Modeling Methodsmentioning

confidence: 99%