Open AccessGiant enhancement of harmonic generation in all-dielectric resonant waveguide gratings of quasi-bound states in the continuum
Author(s) -
Tingyin Ning,
Xin Li,
Yan Zhao,
Luying Yin,
Yanyan Huo,
Lina Zhao,
Qing-Yang Yue
Publication year - 2020
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.409276
Subject(s) - grating , materials science , second harmonic generation , dielectric , optics , optoelectronics , photonics , guided mode resonance , planar , waveguide , nonlinear optics , silicon nitride , resonance (particle physics) , silicon , diffraction grating , physics , laser , computer graphics (images) , particle physics , computer science
We report the giant enhanced optical harmonic generation in all-dielectric silicon nitride (SiN) based resonant waveguide gratings (RWGs) of quasi-bound states in the continuum (BICs) of ultra-high Q factor and localized field. The BICs are realized by tuning the excitation of the guided modes modulated by geometry parameters of four-part grating layer. At a feasible structure of quasi-BIC for nanofabrication, the SHG and THG are enhanced by 10 3 and 10 6 , compared with those from the RWGs of traditional two-part grating layer, respectively, and even up to 10 8 and 10 10 compared with those from the planar SiN film, respectively. The resonance wavelength of quasi-BICs can be effectively tuned by the angle of incidence, while almost not affect the enhancement of SHG and THG response. Our results show that the efficiency harmonic generation from all-nonlinear-dielectric RWGs of quasi-BICs has potential applications for the integrated nonlinear photonic devices.