Trapped modes with extremely high quality factor in a circular array of dielectric nanorods.
Opt Lett
; 43(21): 5403-5406, 2018 Nov 01.
Article
em En
| MEDLINE
| ID: mdl-30383018
ABSTRACT
In this Letter, we investigate the formation of trapped modes with near-zero group velocities in a ring chain composed of dielectric nanorods. Two kinds of bound modes are successfully identified the regular below-continuum-resonance (BCR) modes formed at the band edge and importantly the quasi-bound-states-in-the-continuum (BIC) trapped modes (similar to the BIC in the equivalent infinite linear chain). The lowest-order trapped mode possesses the highest Q factor, which scales exponentially with the number of nanorods N as Qâ¼exp(0.325N) for the BCR and Qâ¼exp(0.662N) for the quasi-BIC. Interestingly, a moderate high Q factor â¼105 can be obtained for the quasi-BIC mode even with a very small N=8. This suggests that our nanorod-based ring resonator possesses a clear advantage over the linear chain for the same N. Our findings greatly expand the application scope of BIC-based phenomena.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Opt Lett
Ano de publicação:
2018
Tipo de documento:
Article