From symmetric to asymmetric bowtie nanoantennas: electrostatic conformal mapping perspective

Nanophotonics

article

Victor Pacheco-Peña¹  Rúben A. Alves²  Miguel Navarro-Cía² 

[1] School of Engineering, Newcastle University, United Kingdom;School of Physics and Astronomy, University of Birmingham, United Kingdom

关键词: conformal mapping;    nanoantennas;    plasmonics;   

DOI  :  10.1515/nanoph-2019-0488

学科分类：社会科学、人文和艺术（综合）

来源: De Gruyter

【 摘 要 】

Plasmonic nanoantennas have revolutionized the way we study and modulate light–matter interaction. Due to nanofabrication limitations, dimer-type nanoantennas always exhibit some degree of asymmetry, which is desirable in some cases. For instance, in sensing applications, asymmetry is sometimes induced by design in plasmonic nanoantennas to favor higher order nonradiative modes with sharp Fano line shapes. Regardless of the actual origin of the asymmetry, unintentional or intentional, an analytical frame that can deal with it in a seamless manner would be beneficial. We resort to conformal mapping for this task and we track the influence of the degree of asymmetry of the circular sectors composing gold bowtie nanoantennas on the nonradiative Purcell enhancement of a nearby nanoemitter. This manuscript reviews the contributions of conformal mapping to plasmonic nanoantennas and illustrates the advantages of the elegant analytical solution provided by conformal mapping to grasp physical insights, which can serve as a springboard for new plasmonic asymmetric nanoantenna designs.

【 授权许可】

CC BY