Dynamically controlling local field enhancement at an epsilon-near-zero/dielectric interface via nonlinearities of an epsilon-near-zero medium

Nanophotonics

article

Alexander Baev¹  Paras N. Prasad¹  M. Zahirul Alam²  Robert W. Boyd² 

[1] The Department of Chemistry, The Institute for Lasers, University at Buffalo;Department of Physics, University of Ottawa;The Institute of Optics, University of Rochester

关键词: epsilon-near-zero;    local field;    nonlinear effects;   

DOI  :  10.1515/nanoph-2020-0490

学科分类：社会科学、人文和艺术（综合）

来源: De Gruyter

【 摘 要 】

For p-polarized light incident on an interface between an ordinary dielectric and an epsilon-near-zero (ENZ) material, an enhancement of the component of the electric field, normal to this interface, has been shown to occur. This local field enhancement holds great promise for amplifying nonlinear optical processes and for other applications requiring ultrastrong local fields in epsilon-near-zero based technologies. However, the loss associated with the imaginary part of the dielectric constant of an epsilon-near-zero material can greatly suppress the field enhancement factor. In this study, we analyze, using density matrix formalism, the field enhancement factor for a saturable two-level system that exhibits second- and third-order nonlinearities. We show that, in such a system, an almost lossless ENZ response can arise as a consequence of saturable nonlinearity and that the local field enhancement factor can be readily controlled dynamically by adjusting the intensity of the incident electromagnetic wave. Our findings provide for the first time a pathway to design a material exhibiting an external field responsive epsilon-near-zero behavior for applications in nonlinear photonics.

【 授权许可】

CC BY