Bound states in the continuum in composite structures consisting of two dielectric diffraction gratings with Lorentzian line shape

2020 ◽  
Author(s):  
Nikita Golovastikov ◽  
Dmitry Bykov ◽  
Leonid Doskolovich
Keyword(s):  
Line Shape ◽  
Composite Structures ◽  
Bound States ◽  
Diffraction Gratings ◽  
Lorentzian Line ◽  
Lorentzian Line Shape ◽  
The Continuum

scholarly journals Exceptional points in composite structures consisting of two dielectric diffraction gratings with Lorentzian line shape

2021 ◽  
Vol 2015 (1) ◽  
pp. 012049
Author(s):  
Nikita Golovastikov ◽  
Dmitry Bykov ◽  
Leonid Doskolovich
Keyword(s):  
Composite Structure ◽  
Composite Structures ◽  
Diffraction Gratings ◽  
Scattering Matrix ◽  
Matrix Formalism ◽  
Exceptional Points ◽  
Lorentzian Line ◽  
Analytical Approximations ◽  
Lorentzian Profile ◽  
Analytical Expressions

Abstract Using scattering matrix formalism we derive analytical expressions for the eigenmodes of a composite structure consisting of two dielectric diffraction gratings with Lorentzian profile in reflection. Analyzing these expressions we prove formation of two distinct pairs of exceptional points, provide analytical approximations for their coordinates and by rigorous simulation demonstrate eigenmodes interchange as a result of encircling said exceptional points.

scholarly journals Integrated diffraction gratings on the Bloch surface wave platform supporting bound states in the continuum

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Evgeni A. Bezus ◽  
Dmitry A. Bykov ◽  
Leonid L. Doskolovich
Keyword(s):  
Surface Wave ◽  
Bound States ◽  
Transverse Electric ◽  
Diffraction Gratings ◽  
Incidence Geometry ◽  
Spectral Filters ◽  
Beam Splitters ◽  
High Q ◽  
Bloch Surface Wave ◽  
The Continuum

Abstract We propose and theoretically and numerically investigate integrated diffraction gratings for the Bloch surface wave (BSW) platform, which have subwavelength or near-subwavelength period. We demonstrate that, in the oblique incidence geometry of a transverse-electric polarized BSW and with a properly chosen band gap configuration of the photonic crystal supporting the surface waves, the proposed structures operate in the scattering-free regime, when the energy of the incident BSW is divided between the reflected and transmitted BSWs with the same polarization corresponding to the propagating diffraction orders of the grating, and not scattered away from the propagation surface. In this regime, the studied integrated gratings support high-Q resonances and bound states in the continuum not only in the subwavelength case when only the specular (zeroth) diffraction orders propagate, but also in the case when non-evanescent zeroth and −1st diffraction orders satisfy the so-called Littrow mounting condition. The proposed integrated gratings on the BSW platform can be used as efficient narrowband spatial or spectral filters operating in reflection, or as BSW beam splitters or deflectors operating in transmission. The obtained results may find application in two-dimensional photonic circuits for steering the BSW propagation.

scholarly journals Creatine and phosphocreatine mapping of mouse skeletal muscle by a polynomial and Lorentzian line-shape fitting CEST method

2018 ◽  
Vol 81 (1) ◽  
pp. 69-78 ◽  
Author(s):  
Lin Chen ◽  
Peter B. Barker ◽  
Robert G. Weiss ◽  
Peter C. M. van Zijl ◽  
Jiadi Xu
Keyword(s):  
Skeletal Muscle ◽  
Line Shape ◽  
Shape Fitting ◽  
Mouse Skeletal Muscle ◽  
Lorentzian Line ◽  
Lorentzian Line Shape

Bestimmung kernresonanzspektroskopischer Parameter durch Lorentz-Kurven-Form-Analyse: I [C6F5Si(CH3)2]2 / Determination of NMR Parameters by Lorentzian-Line-Shape-Analysis I: [C6F5Si(CH3)2]2

1975 ◽  
Vol 30 (2) ◽  
pp. 175-179 ◽  
Author(s):  
Gerhard Hägele ◽  
Volker Lueg
Keyword(s):  
Shape Analysis ◽  
Line Shape ◽  
Computer Programs ◽  
Lorentzian Line ◽  
Nmr Parameters ◽  
Line Shape Analysis ◽  
Lorentzian Line Shape ◽  
Set Up

Abstract The set-up of digital-out-put for HR-CW-NMR-spectrometers and computer-programs suitable for Lorentzian-line-shape-analysis is reported. The values for 5JHF AND 6JHF IN [C6F5Si(CH3)2]2 are determined.

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