Mie scattering as a cascade of Fano resonances

Abstract The constructive interference of light reflecting on the inner surface of a dielectric sphere results in a rich Mie scattering spectrum. Each resonance can be understood through a quantum-mechanical analogy, while the structure of the full spectrum is predicted to be a series of Fano resonances. However, the overlap of all the different modes results in such a complex spectrum that an intuitive understanding of the full, underlying structure is still missing. Here we present a directional Mie spectrum obtained by selecting a particular polarization and direction of the scattering of levitating water droplets. We find a significantly simplified spectrum organized in distinct, consecutive Mie Fano Combs composed of equidistant resonances that smoothly evolve from wide Lorentzians into sharp Fano profiles. We then fully explain all these characteristics by expanding on the quantum-mechanical analogy. This makes it possible to understand Mie spectra intuitively without the need for computational simulations.

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Macrostructure and microphysics of Saturn's E-ring

International Astronomical Union Colloquium ◽

10.1017/s0252921100101691 ◽

1984 ◽

Vol 75 ◽

pp. 607-613 ◽

Cited By ~ 2

Author(s):

Kevin D. Pang ◽

Charles C. Voge ◽

Jack W. Rhoads

Keyword(s):

Size Distribution ◽

Spherical Shape ◽

Mie Scattering ◽

Narrow Size Distribution ◽

Electrostatic Levitation ◽

Volcanic Origin ◽

Micron Diameter

Abstract.All observed optical and infrared properties of Saturn's E-ring can be explained in terms of Mie scattering by a narrow size distribution of ice spheres of 2 - 2.5 micron diameter. The spherical shape of the ring particles and their narrow size distribution imply a molten (possibly volcanic) origin on Enceladus. The E-ring consists of many layers, possibly stratified by electrostatic levitation.

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Atmospheric Observation by a Laser Radar Using Raman Scattering and Mie Scattering

IEEJ Transactions on Electronics Information and Systems ◽

10.1541/ieejeiss.123.1714 ◽

2003 ◽

Vol 123 (10) ◽

pp. 1714-1720 ◽

Cited By ~ 2

Author(s):

Tetsuo Fukuchi ◽

Takuya Nayuki ◽

Takashi Fujii ◽

Koshichi Nemoto

Keyword(s):

Raman Scattering ◽

Mie Scattering ◽

Laser Radar

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Mie scattering measurements of scalar probability density functions in compressible mixing layers

10.2514/6.1991-1686 ◽

1991 ◽

Cited By ~ 3

Author(s):

N. MESSERSMITH ◽

J. DUTTON ◽

H. KRIER

Keyword(s):

Probability Density ◽

Mie Scattering ◽

Probability Density Functions ◽

Mixing Layers ◽

Density Functions ◽

Scattering Measurements

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Mathematical modelling of remote detection of molecular air pollutants

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19871397 ◽

1987 ◽

Vol 52 (6) ◽

pp. 1397-1406

Author(s):

František Zrcek ◽

Milan Horák

Keyword(s):

Atmospheric Aerosols ◽

Air Pollutants ◽

Complex Refractive Index ◽

Mie Scattering ◽

Heat Emission ◽

Remote Detection ◽

Radiation Absorption ◽

Variable Concentration ◽

Lidar Equation ◽

Optical Pathway

A model of remote detection of molecular air pollutants is devised based on the lidar equation. The various kinds of interaction of radiation with matter, viz. absorption, induced fluorescence, and Raman scattering, are taken into account; detection of either scattered or reflected signal is considered. The reflection is assumed to be either axial, using a retroreflector, or omnidirectional from a field target. Based on this model, an algorithm was set up for simulation of the different variants of the experiment, making allowance for a generally variable concentration of the compound along the optical pathway of the light beam. The basic atmospheric processes, viz. radiation absorption by the backround, heat emission, turbulence, and the effect of atmospheric aerosols, are treated, and the last of them is found to play the major role. Aerosols are looked upon as a source of the Mie scattering and they are described by distribution equations with respect to the particle size and the complex refractive index. The variable concentration of the aerosol along the optical pathway and the simultaneous effect of a higher numberof aerosol types are included.

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High-Resolution Photoabsorption Spectrum of Cs+ (5p61So + 5p5ns, nd) Between 504A and 600A using a Laser Ionized Cs Vapor Column

International Astronomical Union Colloquium ◽

10.1017/s0252921100085481 ◽

1984 ◽

Vol 86 ◽

pp. 124-124

Author(s):

T.J. McIlrath ◽

V. Kaufman ◽

J. Sugar ◽

W.T. Hill ◽

D. Cooper

Keyword(s):

High Resolution ◽

Laser Pulse ◽

High Voltage ◽

Power Output ◽

Random Phase ◽

Grazing Incidence ◽

Fano Resonances ◽

Line Shapes ◽

Phase Calculation ◽

Photoabsorption Spectrum

Rapid ionization of Cs vapor in a heat pipe at 0.05 torr was achieved by pumping the 6s 2S½ – 7p 2P½ transition (f=0.007)1 with a flash-pumped dye laser at 4593.2A and I MW power output. Photoabsorptian initiated at the end of the laser pulse(≃ 0.5/s) showed the 5p5ns and nd series below and above the 5p52P3/2 threshold at 535.4A. Broad Beutler - Fano resonances appeared in the d series above threshold. The spectrum was recorded photographically on a 10.7m grazing incidence spectrograph using a continuum background generated by a BRV high-voltage spark source with a uranium anode. We will compare the line-shapes and the quantum defect (Lu-Fano2) plot with the predictions of a relativistic random phase calculation.

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Three-component modelling of C-rich AGB star winds – V. Effects of frequency-dependent radiative transfer including drift★

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa2714 ◽

2020 ◽

Vol 499 (2) ◽

pp. 1531-1560

Author(s):

Christer Sandin ◽

Lars Mattsson

Keyword(s):

Radiative Transfer ◽

Mass Loss ◽

Density Ratio ◽

Mie Scattering ◽

Speed Ratio ◽

Exponential Dependence ◽

Frequency Dependent ◽

Wind Velocities ◽

Drift Models ◽

Loss Rates

ABSTRACT Stellar winds of cool carbon stars enrich the interstellar medium with significant amounts of carbon and dust. We present a study of the influence of two-fluid flow on winds where we add descriptions of frequency-dependent radiative transfer (RT). Our radiation hydrodynamic models in addition include stellar pulsations, grain growth and ablation, gas-to-dust drift using one mean grain size, dust extinction based on both the small particle limit (SPL) and Mie scattering, and an accurate numerical scheme. We calculate models at high spatial resolution using 1024 gridpoints and solar metallicities at 319 frequencies, and we discern effects of drift by comparing drift models to non-drift models. Our results show differences of up to 1000 per cent in comparison to extant results. Mass-loss rates and wind velocities of drift models are typically, but not always, lower than in non-drift models. Differences are larger when Mie scattering is used instead of the SPL. Amongst other properties, the mass-loss rates of the gas and dust, dust-to-gas density ratio, and wind velocity show an exponential dependence on the dust-to-gas speed ratio. Yields of dust in the least massive winds increase by a factor 4 when drift is used. We find drift velocities in the range $10\!-\!67\, \mbox{km}\, \mbox{s}^{-1}$, which is drastically higher than in our earlier works that use grey RT. It is necessary to include an estimate of drift velocities to reproduce high yields of dust and low wind velocities.

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Active nonlocal metasurfaces

Nanophotonics ◽

10.1515/nanoph-2020-0375 ◽

2020 ◽

Vol 10 (1) ◽

pp. 655-665

Author(s):

Stephanie C. Malek ◽

Adam C. Overvig ◽

Sajan Shrestha ◽

Nanfang Yu

Keyword(s):

Bound States ◽

Fano Resonances ◽

Spatial Control ◽

Technical Challenge ◽

Materials Engineering ◽

Narrow Bandwidth ◽

Wavefront Shaping ◽

Mechanical Stretching ◽

Proof Of Principle ◽

The Continuum

AbstractActively tunable and reconfigurable wavefront shaping by optical metasurfaces poses a significant technical challenge often requiring unconventional materials engineering and nanofabrication. Most wavefront-shaping metasurfaces can be considered “local” in that their operation depends on the responses of individual meta-units. In contrast, “nonlocal” metasurfaces function based on the modes supported by many adjacent meta-units, resulting in sharp spectral features but typically no spatial control of the outgoing wavefront. Recently, nonlocal metasurfaces based on quasi-bound states in the continuum have been shown to produce designer wavefronts only across the narrow bandwidth of the supported Fano resonance. Here, we leverage the enhanced light-matter interactions associated with sharp Fano resonances to explore the active modulation of optical spectra and wavefronts by refractive-index tuning and mechanical stretching. We experimentally demonstrate proof-of-principle thermo-optically tuned nonlocal metasurfaces made of silicon and numerically demonstrate nonlocal metasurfaces that thermo-optically switch between distinct wavefront shapes. This meta-optics platform for thermally reconfigurable wavefront shaping requires neither unusual materials and fabrication nor active control of individual meta-units.

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Graphene–polyimide-integrated metasurface for ultrasensitive modulation of higher-order terahertz fano resonances at the Dirac point

Applied Surface Science ◽

10.1016/j.apsusc.2021.150182 ◽

2021 ◽

pp. 150182

Author(s):

Maosheng Yang ◽

Tengteng Li ◽

Ju Gao ◽

Xin Yan ◽

Lanju Liang ◽

...

Keyword(s):

Dirac Point ◽

Higher Order ◽

Fano Resonances

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