Carbon nanotube on Si photonics
Semiconducting single walled carbon nanotubes (s-SWNT) have an immense potential for the development of active opto-electronic functionalities in ultra-compact hybrid photonic circuits. Specifically, s-SWNT have been identified as a very promising solution to implement light sources in the silicon photonics platform. Still, two major challenges remain to fully exploit the potential of this hybrid technology: the limited interaction between s-SWNTs and Si waveguides and the low quantum efficiency of s-SWNTs emission. Silicon micro-ring resonators have the potential to overcome these limitations, by providing enhanced light-s-SWNT interaction through resonant light recirculation in micro-ring resonators or photonic crystal cavities.
Within an active collaboration with Dr. Arianna Filoramp (CEA-Saclay) and other partners, our works aim to integrate polymer materials doped with carbon nanotubes prepared in thin film for co-integration with silicon photonics devices for the realization of active devices. Significant results have been achieved in recent years. The following articles provides one example.
We show that Si micro-ring resonators can provide chirality-wise photoluminescence resonance enhancement, releasing a new degree of freedom to tailor s-SWNT optical properties. Specifically, we demonstrated that judicious design of the micro-ring geometry allows selectively promoting the emission enhancement of either (8,6) or (9,7) chiralities present in a high-purity polymer-sorted s-SWNT solution. In addition, we present an analysis of nanometric-sized silicon-on-insulator waveguides that predicts stronger light-s-SWNT interaction for transverse-magnetic (TM) modes than for conventionally used transverse-electric (TE) modes. Finally, we exploit selective s-SWNT deposition, based on interaction windows defined in the chip cladding, to yield a remarkably large off-resonance rejection of s-SWNT emission exceeding 15dB.
"Tailoring carbon nanotubes optical properties through chirality-wise silicon ring resonators", Elena Durán-Valdeiglesias, Weiwei Zhang, Carlos Alonso-Ramos, Samuel Serna, Xavier Le Roux, Delphine Maris-Morini, Niccolò Caselli, Francesco Biccari, Massimo Gurioli, Arianna Filoramo, Eric Cassan, Laurent Vivien