Bound states in the continuum and strong phase resonances in integrated Gires-Tournois interferometer

Nanophotonics

Bezus Evgeni A.¹  Bykov Dmitry A.¹  Doskolovich Leonid L.¹ 

[1] Image Processing Systems Institute – Branch of the Federal Scientific Research Centre “Crystallography and Photonics” of Russian Academy of Sciences, 151 Molodogvardeyskaya St., Samara 443001, Russia;

关键词: bound states in the continuum;    resonance;    mode coupling;    integrated optics;   

DOI  :  10.1515/nanoph-2019-0316

来源: DOAJ

【 摘 要 】

Photonic bound states in the continuum (BICs) are eigenmodes with an infinite lifetime, which coexist with a continuous spectrum of radiating waves. BICs are not only of great theoretical interest but also have a wide range of practical applications, e.g. in the design of optical resonators. Here, we study this phenomenon in a new integrated nanophotonic element consisting of a single dielectric ridge terminating an abruptly ended slab waveguide. This structure can be considered as an on-chip analog of the Gires-Tournois interferometer (GTI). We demonstrate that the proposed integrated structure supports high-Q phase resonances and robust BICs. We develop a simple but extremely accurate coupled-wave model that clarifies the physics of BIC formation and enables predicting BIC locations. The developed model shows that the studied BICs are topologically protected and describes the strong phase resonance effect that occurs when two BICs with opposite topological charges annihilate.

【 授权许可】

Unknown