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

Nanophotonics

article

Yang Li¹  Wenguo Zhu¹  Jianhui Yu¹  Huihui Lu¹  Zhe Chen¹  Zhijin Huang¹  Zhan Sui²  Huajiang Chen¹  Xinyue Zhang¹  Weian Huang¹  Heyuan Guan¹  Wentao Qiu³  Jiangli Dong¹ 

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

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

DOI  :  10.1515/nanoph-2020-0222

学科分类：社会科学、人文和艺术（综合）

来源: De Gruyter

【 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/cm 2 pump intensity via the excitation of anapole in lithium niobite (LiNbO 3 , or LN) nanodisk through the dominating d 33 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】

CC BY