Low Loss Vertical TiO2/Polymer Hybrid Nano-Waveguides

Autor: Isaac Doughan, Kehinde Oyemakinwa, Olli Ovaskainen, Matthieu Roussey
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: Nanomaterials, Vol 13, Iss 3, p 469 (2023)
Druh dokumentu: article
ISSN: 13030469
2079-4991
DOI: 10.3390/nano13030469
Popis: This article proposes a novel demonstration of a low-loss polymer channel hybridized with a titania core leading to a nano-waveguide elongated in the normal direction to the substrate. It is aimed at using the quasi-transverse magnetic (TM) mode as the predominant mode in compact photonic circuitry. A detailed design analysis shows how a thin layer of a higher-refractive index material in a trench within the core of the waveguide can increase the confinement and reduce the propagation losses. This thin layer, produced by atomic layer deposition, covers the entire polymer structure in a conformal manner, ensuring both a reduction of the surface roughness and a stronger field confinement. The trench can be made at any place within the polymer channel and therefore its position can be tuned to obtain asymmetric modal distribution. The waveguide is demonstrated at telecom wavelengths, although the material’s properties enable operation over a large part of the electromagnetic spectrum. We measured propagation losses as low as 1.75 ± 0.32 dB/cm in a 200 nm × 900 nm section of the waveguide core. All processes being mass-production compatible, this study opens a path towards easier integrated-component manufacture.
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