Carbon-nanotube-on-waveguide thermo-optic tuners

• Published in: Optics letters Vol. 43; no. 21; p. 5194
• Main Authors: Dash, Aneesh, Mere, Viphretuo, Gangavarapu, P R Y, Nambiar, S R, Selvaraja, S K, Naik, A K
• Format: Journal Article
• Language: English
• Published: United States 01.11.2018
• ISSN: 1539-4794
• DOI: 10.1364/OL.43.005194

We demonstrate on-waveguide thermo-optic tuners based on solution-processed metallic carbon nanotubes (CNTs) on silicon-on-insulator (SOI) and silicon nitride (SiN) microring resonators operating around 1550 nm. On SOI microring resonators using planarized wire waveguides, a thermo-optic power efficiency of 29 mW/FSR and a thermal transient of 1.3 μs are achieved. The heater is shown to be more power-efficient than conventional metal heaters and has lower thermal transient than both metal heaters and graphene-based heaters. On SiN microring resonators using rib waveguides, improvement in power efficiency with an increase in coverage of CNTs is demonstrated, indicating localized heating using the CNTs; this is favorable for low thermal cross-talk. An optimal power efficiency of 142 mW/FSR and a thermal transient of 5.8 μs are achieved.