Coherent perfect absorber and laser induced by directional emissions in the non-Hermitian photonic crystals.
Opt Express
; 31(25): 41276-41291, 2023 Dec 04.
Article
em En
| MEDLINE
| ID: mdl-38087530
ABSTRACT
In this study, we propose the application of non-Hermitian photonic crystals (PCs) with anisotropic emissions. Unlike the ring of exceptional points (EPs) found in isotropic non-Hermitian PCs, the EPs of anisotropic non-Hermitian PCs appear as symmetrical lines about the Γ point. The formation of EPs is related to the non-Hermitian strength and the real spectrum appears in the ΓY direction. The PCs have been validated as the complex conjugate medium (CCM) by effective medium theory (EMT). Conversely, EMT indicates that the effective refractive index has a large imaginary part along the ΓX direction, which forms an evanescent wave inside the PCs. Consequently, coherent perfect absorption (CPA) and laser can be achieved in the directional emission of the ΓY. The outgoing wave in the ΓX direction is weak, which can significantly reduce the losses and electromagnetic interference. The non-Hermitian PCs enable many fascinating applications such as signal amplification, collimation, and angle sensors.
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1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Opt Express
Assunto da revista:
OFTALMOLOGIA
Ano de publicação:
2023
Tipo de documento:
Article