Ultralow mode-volume photonic crystal nanobeam cavities for high efficiency coupling to individual carbon nanotube emitters

TL;DR

This paper demonstrates highly efficient coupling of individual carbon nanotubes to ultralow mode-volume photonic crystal nanobeam cavities, highlighting the advantages of air-mode cavities for nanoscale emitter integration.

Contribution

It introduces ultralow mode-volume air-mode photonic crystal nanobeam cavities that significantly improve coupling efficiency to nanoscale emitters like carbon nanotubes.

Findings

Air-mode cavities couple more efficiently than dielectric-mode.

Spontaneous emission coupling factors reach up to 0.85.

Ultralow mode-volume cavities enhance emitter coupling efficiency.

Abstract

We report on high efficency coupling of individual air-suspended carbon nanotubes to silicon photonic crystal nanobeam cavities. Photoluminescence images of dielectric- and air-mode cavities reflect their distinctly different mode profiles and show that fields in the air are important for coupling. We find that the air-mode cavities couple more efficiently, and estimated spontaneous emission coupling factors reach a value as high as 0.85. Our results demonstrate advantages of ultralow mode-volumes in air-mode cavities for coupling to low-dimensional nanoscale emitters.