Effect of symmetry breaking on bound states in the continuum in waveguide arrays

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985882%3A_____%2F22%3A00558679" target="_blank" >RIV/67985882:_____/22:00558679 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216305:26210/22:PU144810

Výsledek na webu

<a href="https://doi.org/10.1103/PhysRevA.105.063505" target="_blank" >https://doi.org/10.1103/PhysRevA.105.063505</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1103/PhysRevA.105.063505" target="_blank" >10.1103/PhysRevA.105.063505</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Effect of symmetry breaking on bound states in the continuum in waveguide arrays

Popis výsledku v původním jazyce

We developed the theoretical framework based on the coupled-mode theory which describes spectral and scattering properties of the photonic analog of an extended Fano-Anderson model???a waveguide array with two additional side-coupled waveguides. The structure supports a rich spectrum of eigenmodes, including bound state in the continuum (BIC) and other bound and leaky modes, which can be classified according to the relation between the self-coupling coefficients and eigenvalues. We focus on the structures with broken vertical symmetry with their band structures revealing interesting phenomena, such as exceptional points and level repulsion, and offer a lossless platform for PT-symmetry phase transition. We interpreted the resonant features in the scattering spectra through a generalized Weierstrass factorization. The resonance related with quasi-BIC arises from the interference between two leaky modes: one of them representing a continuum spectrum and the other (quasi-BIC) discrete state. The reflectance near the resonance can be rewritten into the form of the Fano formula where the shape parameter f can be expressed in terms of the poles associated with the two modes. Our approach provides a flexible framework which allows to interpret and to engineer the resonant properties of more complex systems.

Název v anglickém jazyce

Effect of symmetry breaking on bound states in the continuum in waveguide arrays

Popis výsledku anglicky

We developed the theoretical framework based on the coupled-mode theory which describes spectral and scattering properties of the photonic analog of an extended Fano-Anderson model???a waveguide array with two additional side-coupled waveguides. The structure supports a rich spectrum of eigenmodes, including bound state in the continuum (BIC) and other bound and leaky modes, which can be classified according to the relation between the self-coupling coefficients and eigenvalues. We focus on the structures with broken vertical symmetry with their band structures revealing interesting phenomena, such as exceptional points and level repulsion, and offer a lossless platform for PT-symmetry phase transition. We interpreted the resonant features in the scattering spectra through a generalized Weierstrass factorization. The resonance related with quasi-BIC arises from the interference between two leaky modes: one of them representing a continuum spectrum and the other (quasi-BIC) discrete state. The reflectance near the resonance can be rewritten into the form of the Fano formula where the shape parameter f can be expressed in terms of the poles associated with the two modes. Our approach provides a flexible framework which allows to interpret and to engineer the resonant properties of more complex systems.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

20201 - Electrical and electronic engineering

Projekt

<a href="/cs/project/GA19-00062S" target="_blank" >GA19-00062S: Pokročilé funkcionality v subvlnových fotonických a plazmonických strukturách</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2022

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Physical Review A

ISSN

2469-9926

e-ISSN

2469-9934

Svazek periodika

105

Číslo periodika v rámci svazku

6

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

7

Strana od-do

063505

Kód UT WoS článku

000809499800005

EID výsledku v databázi Scopus

2-s2.0-85131892287