Giant enhancement of second harmonic generation from monolayer 2D materials placed on photonic moiré superlattice
Ning Tingyin,
Zhao Lina,
Huo Yanyan,
Cai Yangjian,
Ren Yingying
Affiliations
Ning Tingyin
Shandong Provincial Engineering and Technical Center of Light Manipulations & Shandong Provincial Key Laboratory of Optics and Photonic Device, School of Physics and Electronics, Shandong Normal University, Jinan250358, China
Zhao Lina
Shandong Provincial Engineering and Technical Center of Light Manipulations & Shandong Provincial Key Laboratory of Optics and Photonic Device, School of Physics and Electronics, Shandong Normal University, Jinan250358, China
Huo Yanyan
Shandong Provincial Engineering and Technical Center of Light Manipulations & Shandong Provincial Key Laboratory of Optics and Photonic Device, School of Physics and Electronics, Shandong Normal University, Jinan250358, China
Cai Yangjian
Shandong Provincial Engineering and Technical Center of Light Manipulations & Shandong Provincial Key Laboratory of Optics and Photonic Device, School of Physics and Electronics, Shandong Normal University, Jinan250358, China
Ren Yingying
Shandong Provincial Engineering and Technical Center of Light Manipulations & Shandong Provincial Key Laboratory of Optics and Photonic Device, School of Physics and Electronics, Shandong Normal University, Jinan250358, China
We numerically investigate second harmonic generation (SHG) from a monolayer of 2D-material placed on photonic moiré superlattice fabricated by dielectric materials. The greatly enhanced local field at the resonance modes of moiré superlattice can dramatically boost the SHG response in 2D materials. Considering a typical 2D-material MoS2 monolayer placed on a photonic moiré superlattice of a twist angle 9.43°, the maximum SHG conversion efficiency reaches up to 10−1 at a relatively low intensity of fundamental light 1 kW/cm2, which is around 14 orders of magnitude larger than that from the monolayer placed on a flat dielectric slab without moiré superlattices. The SHG conversion efficiency from the monolayer can be further enhanced with the decrease of the twist angles of moiré superlattice due to the even more confinement of local field. The flat bands in the moiré superlattices formed by the small twist angles can particularly ensure the efficiency even under wide-angle illuminations. The results indicate that photonic moiré superlattice which can tightly confine light is a promising platform for efficient nonlinear optics.
