Low-Loss and Compact Silicon Rib Waveguide Bends

[EN] Waveguide bends support intrinsically leaky propagation modes due to unavoidable radiation losses. It is known that the losses of deep-etched/strip waveguide bends increase inevitably for decreasing radius. Here, we theoretically and experimentally demonstrate that this result is not directly a...

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Detalhes bibliográficos
Autores: Brimont, Antoine Christian Jacques, Hu, X., Cueff, Sébastien, Rojo-Romeo, Pedro, Saint Girons, Guillaume, Zanzi, Andrea, Orobtchouk, Regis, Griol Barres, Amadeu, Sanchis Kilders, Pablo|||0000-0003-2984-4218
Formato: artículo
Fecha de publicación:2016
País:España
Recursos:Universitat Politècnica de València (UPV)
Repositorio:RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
Idioma:inglés
OAI Identifier:oai:riunet.upv.es:10251/79149
Acesso em linha:https://riunet.upv.es/handle/10251/79149
Access Level:acceso abierto
Palavra-chave:Integrated optics
Silicon photonics
Rib waveguides
Waveguide bends
Optical design
TEORIA DE LA SEÑAL Y COMUNICACIONES
Descrição
Resumo:[EN] Waveguide bends support intrinsically leaky propagation modes due to unavoidable radiation losses. It is known that the losses of deep-etched/strip waveguide bends increase inevitably for decreasing radius. Here, we theoretically and experimentally demonstrate that this result is not directly applicable to shallow-etched/rib waveguide bends. Indeed, we show that the total losses caused by the bends reach a local minimum value for a certain range of compact radii and rib waveguide dimensions. Specifically, we predicted the minimum intrinsic losses < 0.1 dB/90 degrees turn within the range of 25-30 mu m bend radii in a 220 nm-thick and 400 nm-wide silicon rib waveguide with 70 nm etching depth. This unexpected outcome, confirmed by experimental evidence, is due to the opposite evolution of radiation (bending) losses and losses caused by the coupling to lateral slab modes (slab leakage) as a function of the bend radius, hence creating an optimum loss region. This result may have important implications for the design of compact and low-loss silicon nanophotonic devices.