Optical anapole mode in nanostructured lithium niobate for enhancing second harmonic generation

Nanophotonics

Zhang Xinyue¹  Dong Jiangli¹  Chen Zhe¹  Li Yang¹  Huang Zhijin¹  Zhu Wenguo¹  Yu Jianhui¹  Guan Heyuan¹  Lu Huihui¹  Huang Weian¹  Chen Huajiang¹  Qiu Wentao²  Sui Zhan³ 

[1] Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Jinan University, Guangzhou 510632, P.R. China;Key Laboratory of Optoelectronic Information and Sensing Technologies of Guangdong Higher Education Institutes, Jinan University, Guangzhou 510632, China;Shanghai Institute of Laser Plasma, China Academy of Engineering Physics, Shanghai, 201800, China;

关键词: anapole;    hyperbolic metamaterials;    lithium niobate;    second harmonic generation (shg);   

DOI  :  10.1515/nanoph-2020-0222

来源: DOAJ

【 摘 要 】

Second harmonic generation (SHG) with a material of large transparency is an attractive way of generating coherent light sources at exotic wavelength range such as VUV, UV and visible light. It is of critical importance to improve nonlinear conversion efficiency in order to find practical applications in quantum light source and high resolution nonlinear microscopy, etc. Here an enhanced SHG with conversion efficiency up to 10−2% at SH wavelength of 282.7 nm under 11 GW/cm2 pump intensity via the excitation of anapole in lithium niobite (LiNbO3, or LN) nanodisk through the dominating d33 nonlinear coefficient is investigated. The anapole has advantages of strongly suppressing far-field scattering and well-confined internal field which helps to boost the nonlinear conversion. Anapoles in LN nanodisk is facilitated by high index contrast between LN and substrate with properties of near-zero-index via hyperbolic metamaterial structure design. By tailoring the multi-layers structure of hyperbolic metamaterials, the anapole excitation wavelength can be tuned at different wavelengths. It indicates that an enhanced SHG can be achieved at a wide range of pump light wavelengths via different design of the epsilon-near-zero (ENZ) hyperbolic metamaterials substrates. The proposed nanostructure in this work might hold significances for the enhanced light–matter interactions at the nanoscale such as integrated optics.

【 授权许可】

Unknown