Dual bound states in the continuum enhanced second harmonic generation with transition metal dichalcogenides monolayer
连续介质中的双束缚态增强了过渡金属二硫属化物单层的二次谐波产生
遷移金属ジカルコゲニド単分子層による連続体増強第二高調波発生の二重束縛状態
연속체의 이중 결합 상태는 전이 금속 디칼코게나이드 단층을 사용하여 2차 고조파 생성을 강화했습니다
Estados de doble límite en la generación continua mejorada de segundo armónico con monocapa de dicalcogenuros de metales de transición
Double états liés dans la génération de deuxième harmonique améliorée par le continuum avec une monocouche de dichalcogénures de métaux de transition
Двойные связанные состояния в континууме с усиленной генерацией второй гармоники с монослоем дихалькогенидов переходных металлов
Peilong Hong 洪佩龙 ¹, Lei Xu 徐雷 ², Mohsen Rahmani ²
¹ School of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China (UESTC), Chengdu 611731, China
中国 成都 电子科技大学 光电科学与工程学院
² Advanced Optics & Photonics Laboratory, Department of Engineering, School of Science & Technology, Nottingham Trent University, Nottingham NG11 8NS, UK
The emergence of two dimensional (2D) materials has opened new possibilities for exhibiting second harmonic generation (SHG) at the nanoscale, due to their remarkable optical response related to stable excitons at room temperature. However, the ultimate atomic-scale interaction length with light makes the SHG of Transition Metal Dichalcogenides (TMDs) monolayers naturally weak.
Here, we propose coupling a monolayer of TMDs with a photonic grating slab that works with doubly resonant bound states in the continuum (BIC). The BIC slabs are designed to exhibit a pair of BICs, resonant with both the fundamental wave (FW) and the second harmonic wave (SHW). Firstly, the spatial mode matching can be fulfilled by tilting FW's incident angle. We theoretically demonstrate that this strategy leads to more than four orders of magnitude enhancement of SHG efficiency than a sole monolayer of TMDs, under a pump light intensity of 0.1 GW/cm2.
Moreover, we demonstrate that patterning the TMDs monolayer can further enhance the spatial overlap coefficient, which leads to an extra three orders of magnitude enhancement of SHG efficiency. These results demonstrate remarkable possibilities for enhancing SHG with nonlinear 2D materials, opening many opportunities for chip-based light sources, nanolasers, imaging, and biochemical sensing.
