Tuning third harmonic light

27 April 2017:

Researchers from CNBP and The Institute of Photonic Technology (lead author Stephen Warren-Smith pictured), have just had a paper published on tuning third harmonic light generated within exposed-core fibres.

Journal: Optics Letters.

Publication title: Nanofilm-induced spectral tuning of third harmonic generation.

Authors: Stephen C. Warren-Smith, Mario Chemnitz, Henrik Schneidewind, Roman Kostecki, Heike Ebendorff-Heidepriem, Tanya M. Monro and Markus A. Schmidt.

Abstract: Intermodal third-harmonic generation using waveguides is an effective frequency conversion process due to the combination of long interaction lengths and strong modal confinement. Here we introduce the concept of tuning the third harmonic phase-matching condition via the use of dielectric nanofilms located on an open waveguide core. We experimentally demonstrate that tantalum oxide nanofilms coated onto the core of an exposed core fiber allow tuning the third harmonic wavelength over 30 nm, as confirmed by qualitative simulations. Due to its generic character, the presented tuning scheme can be applied to any form of exposed core waveguide and will find applications in fields including microscopy, biosensing, and quantum optics.

The paper is accessible online.