Directional emission of nanoscale chiral sources modified by gap plasmons

Efficient manipulation of the emission direction of a chiral nanoscale light source is significant for information transmission and on-chip information processing. Here, we propose a scheme to control the directionality of nanoscale chiral light sources based on gap plasmons. The gap plasmon mode formed by a gold nanorod and a silver nanowire realizes the highly directional emission of chiral light sources. Based on the optical spin-locked light propagation, the hybrid structure enables the directional coupling of chiral emission to achieve a contrast ratio of 99.5%. The emission direction can be manipulated by tailoring the configuration of the structure, such as the positions, aspect ratios, and orientation of the nanorod. Besides, a great local field enhancement exists for highly enhanced emission rates within the nanogap. This chiral nanoscale light source manipulation scheme provides a way for chiral valleytronics and integrated photonics.

Automated summary

Efficient manipulation of the emission direction of a chiral nanoscale light source is achieved using a scheme based on gap plasmons. Highly directional emission of chiral light sources is realized using a gap plasmon mode formed by a gold nanorod and a silver nanowire. The emission direction can be controlled by modifying the configuration of the structure. Additionally, a strong local field enhancement allows for highly enhanced emission rates within the nanogap. This manipulation scheme provides a way for chiral valleytronics and integrated photonics.