Nonstationary angular distribution of optical field radiance from an isotropic source in sea water

2020 ◽  
Vol 59 (20) ◽  
pp. 6046
Author(s):  
Alexander G. Luchinin ◽  
Mikhail Yu. Kirillin ◽  
Lev S. Dolin
Keyword(s):  
Angular Distribution ◽  
Sea Water ◽  
Optical Field ◽  
Isotropic Source

scholarly journals Open water camouflage via ‘leaky’ light guides in the midwater squid Galiteuthis

2016 ◽  
Vol 13 (119) ◽  
pp. 20160230 ◽  
Author(s):  
Amanda L. Holt ◽  
Alison M. Sweeney
Keyword(s):  
Angular Distribution ◽  
Open Water ◽  
Light Environment ◽  
Cross Sectional ◽  
Isotropic Source ◽  
Vertical Range ◽  
Light Guides

Galiteuthis , a midwater squid, has photophores on the ventral surfaces of its eyes. These photophores emit bioluminescence to counter-illuminate the shadows cast by the eyes in downwelling sunlight, thereby hiding the eyes from upward-looking predators. The photophores consist of laminated fibre-like cells with semi-coaxial protein-dense layers around axial cytoplasm. These cells have been suggested to function as light guides: bioluminescence is an isotropic process used to hide in an anisotropic light environment, so any emission must be reshaped to be effective. We found a wide variation in cross-sectional geometries of photophore cells; some were more efficient at light guiding than others. We used a set of optical models to place these photophores in the context of the radiance where Galiteuthis lives and discovered a possible adaptive reason for this variation. In Galiteuthis 's horizontal and vertical range, ocean radiance is also quite variable. For complete camouflage, photophores must reproduce this variation in radiance using an isotropic source. Our models show that variation in the geometry of the photophore light guides reproduces the predicted variation in ocean radiance experienced by this species. By selectively activating geometrically distinct populations of photophore cells, the animal may reproduce the angular distribution of light at all positions in its habitat.

Electron Scattering in Solids

1990 ◽  
Vol 48 (2) ◽  
pp. 4-5
Author(s):  
Ryuichi Shimizu ◽  
Ze-Jun Ding
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Angular Distribution ◽  
Elastic Scattering ◽  
Electron Scattering ◽  
Cross Sections ◽  
Expansion Method ◽  
Electron Excitation ◽  
Partial Wave Expansion ◽  
Backscattered Electrons

Monte Carlo simulation has been becoming most powerful tool to describe the electron scattering in solids, leading to more comprehensive understanding of the complicated mechanism of generation of various types of signals for microbeam analysis.The present paper proposes a practical model for the Monte Carlo simulation of scattering processes of a penetrating electron and the generation of the slow secondaries in solids. The model is based on the combined use of Gryzinski’s inner-shell electron excitation function and the dielectric function for taking into account the valence electron contribution in inelastic scattering processes, while the cross-sections derived by partial wave expansion method are used for describing elastic scattering processes. An improvement of the use of this elastic scattering cross-section can be seen in the success to describe the anisotropy of angular distribution of elastically backscattered electrons from Au in low energy region, shown in Fig.l. Fig.l(a) shows the elastic cross-sections of 600 eV electron for single Au-atom, clearly indicating that the angular distribution is no more smooth as expected from Rutherford scattering formula, but has the socalled lobes appearing at the large scattering angle.

High-performance light transmission based on graphene plasmonic waveguides

2020 ◽  
Vol 8 (20) ◽  
pp. 6832-6838 ◽  
Author(s):  
Da Teng ◽  
Kai Wang ◽  
Qiongsha Huan ◽  
Weiguang Chen ◽  
Zhe Li
Keyword(s):  
High Performance ◽  
Light Transmission ◽  
Optical Field ◽  
Plasmonic Waveguides ◽  
Rib Waveguide

Tunable ultra-deep subwavelength optical field confinement is reported by using a graphene-coated nanowire-loaded silicon nano-rib waveguide.

Corrosion of Brass in Sea Water

1919 ◽  
Vol 87 (2257supp) ◽  
pp. 211-211
Author(s):  
Paul T. Bruhl
Keyword(s):  
Sea Water
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