Wide-angle ultrasensitive biosensors based on edge states in heterostructures containing hyperbolic metamaterials

Thin films of noble metals with thickness smaller than the wavelength of light constitute one of the most investigated structures in plasmonics. The fact that surface plasmon modes can be excited in these films by different ways and the simplicity of fabrication offer ideal conditions for applications in nanophotonics. The generation of optical modes in coupled Fabry-Pérot planar cavities and their migration to hyperbolic metamaterials is investigated. Coupled Fabry-Pérot cavities behave as simple coupled resonators. When the intra-cavity media have different refractive indices in two or more coupled cavities resonance anti-crossings arise. The application of this kind of strong coupling in sensing is foreseen. Beyond the cavity modes excited by propagating waves, also long range plasmonic guided modes can be excited using emitters or evanescent waves. A periodic structure made by multiple plasmonic films and dielectrica supports bulk plasmons, of large propagation constant and increasing field amplitude. The optical response of these structures approaches that of the hyperbolic metamaterial predicted by the effective medium theory. Light can propagate with full transmission in a structure made of a photonic crystal based on quarter wavelength layers and a second photonic crystal with an overlapping forbidden band, but presenting a non-trivial topological phase achieved by band inversion. This is due to excitation of optical Tamm states at the boundary between both crystals. The extension to multiple optical Tamm states using dielectric and plasmonic materials and the symmetries of the edge states is investigated.

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CBED Shadow Images and Cs:Aberration Measurement

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100055813 ◽

1982 ◽

Vol 40 ◽

pp. 696-697

Author(s):

R. W. Carpenter ◽

I.Y.T. Chan ◽

J. M. Cowley

Keyword(s):

Focal Point ◽

Spherical Aberration ◽

Optic Axis ◽

Wide Angle ◽

Caustic Surface ◽

Convergent Beam

Wide-angle convergent beam shadow images(CBSI) exhibit several characteristic distortions resulting from spherical aberration. The most prominent is a circle of infinite magnification resulting from rays having equal values of a forming a cross-over on the optic axis at some distance before reaching the paraxial focal point. This distortion is called the tangential circle of infinite magnification; it can be used to align and stigmate a STEM and to determine Cs for the probe forming lens. A second distortion, the radial circle of infinite magnification, results from a cross-over on the lens caustic surface of rays with differing values of ∝a, also before the paraxial focal point of the lens.

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Reconstruction of Chitin-Protein Complexes Using Correlation Averaging Methods: Ovipositor of the Ichneumon Fly Megarhyssa

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s1431927600000143 ◽

1980 ◽

Vol 38 ◽

pp. 38-39

Author(s):

L. T. Germinario ◽

J. Blackwell ◽

J. Frank

Keyword(s):

Protein Complexes ◽

Hexagonal Lattice ◽

Uranyl Acetate ◽

Optical Diffraction ◽

Insect Cuticle ◽

High Dose ◽

Wide Angle ◽

X Ray ◽

Averaging Methods ◽

Digital Correlation

This report describes the use of digital correlation and averaging methods 1,2 for the reconstruction of high dose electron micrographs of the chitin-protein complex from Megarhyssa ovipositor. Electron microscopy of uranyl acetate stained insect cuticle has demonstrated a hexagonal array of unstained chitin monofibrils, 2.4−3.0 nm in diameter, in a stained protein matrix3,4. Optical diffraction Indicated a hexagonal lattice with a = 5.1-8.3 nm3 A particularly well ordered complex is found in the ovipositor of the ichneumon fly Megarhyssa: the small angle x-ray data gives a = 7.25 nm, and the wide angle pattern shows that the protein consists of subunits arranged in a 61 helix, with an axial repeat of 3.06 nm5.

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Developmental Risk Through a Wide-Angle Lens

Contemporary Psychology ◽

10.1037/026675 ◽

1987 ◽

Vol 32 (1) ◽

pp. 54-55

Author(s):

Jack P. Shonkoff

Keyword(s):

Wide Angle ◽

Developmental Risk ◽

Wide Angle Lens

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Wide angle view of the Universe

Nature India ◽

10.1038/nindia.2016.86 ◽

2016 ◽

Keyword(s):

Wide Angle ◽

The Universe

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Single-peak-regulation and wide-angle dual-band metamaterial absorber based on hollow-cross and solid-cross resonators

The European Physical Journal Applied Physics ◽

10.1051/epjap/2020200145 ◽

2020 ◽

Vol 91 (3) ◽

pp. 30901

Author(s):

Yibo Tang ◽

Longhui He ◽

Jianming Xu ◽

Hailang He ◽

Yuhan Li ◽

...

Keyword(s):

Transverse Electric ◽

Surface Current ◽

Dielectric Substrate ◽

Transverse Magnetic ◽

Metamaterial Absorber ◽

Absorption Peak ◽

Dual Band ◽

Single Peak ◽

Wide Angle ◽

Surface Current Density

A dual-band microwave metamaterial absorber with single-peak regulation and wide-angle absorption has been proposed and illustrated. The designed metamaterial absorber is consisted of hollow-cross resonators, solid-cross resonators, dielectric substrate and metallic background plane. Strong absorption peak coefficients of 99.92% and 99.55% are achieved at 8.42 and 11.31 GHz, respectively, which is basically consistent with the experimental results. Surface current density and changing material properties are employed to illustrate the absorptive mechanism. More importantly, the proposed dual-band metamaterial absorber has the adjustable property of single absorption peak and could operate well at wide incidence angles for both transverse electric (TE) and transverse magnetic (TM) waves. Research results could provide and enrich instructive guidances for realizing a single-peak-regulation and wide-angle dual-band metamaterial absorber.

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