Efficient Third-Harmonic Generation via Strong Coupling of Quasi-Guided Modes

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Huang, Xin, Lin, Qi, Xia, Sheng-Xuan, Zhai, Xiang, Liu, Gui-Dong
Formato: Preprint
Publicado: 2025
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866912545529397248
author Huang, Xin
Lin, Qi
Xia, Sheng-Xuan
Zhai, Xiang
Liu, Gui-Dong
author_facet Huang, Xin
Lin, Qi
Xia, Sheng-Xuan
Zhai, Xiang
Liu, Gui-Dong
contents Improving the conversion efficiency is critical for advancing nonlinear photonic devices, enabling applications in ultrafast optics, quantum light sources, and high-resolution imaging. Herein, we present a bilayer waveguide integrated with a periodic square nanocube array to enhance third-harmonic generation (THG) efficiency. This structure achieves strong coupling between TE- and TM-polarized quasi-guided mode (QGM) resonances, thereby enabling simultaneous dynamic control of both resonant Q-factor and coupling strength through incident polarization angle. The distinct avoided crossing observed in both reflection spectra and eigenfrequency diagrams indicates the strong coupling regime. This mechanism, facilitated by the inter-mode energy exchange within the hybridized system, results in an enhancement of Q-factor by two orders of magnitude when compared to conventional guided-mode resonances. Simulation results verify an unprecedented maximum Q-factor of 10^12 for the upper-branch mode. Leveraging strong-coupling-induced field enhancement, the system attains THG conversion efficiency of order 10^-2, demonstrating unprecedented nonlinear performance.
format Preprint
id arxiv_https___arxiv_org_abs_2508_14514
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Efficient Third-Harmonic Generation via Strong Coupling of Quasi-Guided Modes
Huang, Xin
Lin, Qi
Xia, Sheng-Xuan
Zhai, Xiang
Liu, Gui-Dong
Optics
78A46, 65Z05
I.4.5; I.4.0
Improving the conversion efficiency is critical for advancing nonlinear photonic devices, enabling applications in ultrafast optics, quantum light sources, and high-resolution imaging. Herein, we present a bilayer waveguide integrated with a periodic square nanocube array to enhance third-harmonic generation (THG) efficiency. This structure achieves strong coupling between TE- and TM-polarized quasi-guided mode (QGM) resonances, thereby enabling simultaneous dynamic control of both resonant Q-factor and coupling strength through incident polarization angle. The distinct avoided crossing observed in both reflection spectra and eigenfrequency diagrams indicates the strong coupling regime. This mechanism, facilitated by the inter-mode energy exchange within the hybridized system, results in an enhancement of Q-factor by two orders of magnitude when compared to conventional guided-mode resonances. Simulation results verify an unprecedented maximum Q-factor of 10^12 for the upper-branch mode. Leveraging strong-coupling-induced field enhancement, the system attains THG conversion efficiency of order 10^-2, demonstrating unprecedented nonlinear performance.
title Efficient Third-Harmonic Generation via Strong Coupling of Quasi-Guided Modes
topic Optics
78A46, 65Z05
I.4.5; I.4.0
url https://arxiv.org/abs/2508.14514