Shaping the optical properties of carbon nanotubes via chirality- selective resonant enhancement in silicon micro-ring resonators

Abstract

International audienceSemiconducting single walled carbon nanotubes (s-SWNT) have an immense potential for the development of light sources in the silicon photonics platform. However, two major challenges still need to be addressed: the limited interaction between s-SWNTs and Si waveguides and the single-chirality selection. Silicon micro-ring resonators may overcome the first limitation by exploiting resonant light recirculation. Here, we demonstrate that Si ring resonators can also provide SWNT chirality-selective photoluminescence resonance enhancement, releasing a new degree of freedom to shape the optical properties of s-SWNT. Specifically, we experimentally show selective emission enhancement of either (8,6) or (8,7) SWNT chiralities present in a high-purity polymer-sorted s-SWNT solution by judicious micro-ring geometry design. In addition, we harness the large index contrast of the Si platform to experimentally demonstrate that, opposite to the common knowledge, transverse-magnetic (TM) optical modes can efficiently interact with drop-casted s-SWNTs arranged along the chip surface