文章基本信息

标题：Highly efficient broadband second harmonic generation mediated by mode hybridization and nonlinearity patterning in compact fiber-integrated lithium niobate nano-waveguides
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作者：Lutong Cai ; Andrey V. Gorbach ; Yiwen Wang 等
期刊名称：Scientific Reports
电子版ISSN：2045-2322
出版年度：2018
卷号：8
期号：1
页码：12478
DOI：10.1038/s41598-018-31017-0
语种：English
出版社：Springer Nature
摘要：The inherent trade-off between efficiency and bandwidth of three-wave mixing processes in χ ₂ nonlinear waveguides is the major impediment for scaling down many well-established frequency conversion schemes onto the level of integrated photonic circuit. Here, we show that hybridization between modes of a silica microfiber and a LiNbO₃ nanowaveguide, amalgamated with laminar χ ₂ patterning, offers an elegant approach for engineering broadband phase matching and high efficiency of three-wave mixing processes in an ultra-compact and natively fiber-integrated setup. We demonstrate exceptionally high normalized second harmonic generation (SHG) efficiency of up to η _nor ≈ 460% W⁻¹ cm⁻², combined with a large phase matching bandwidth of Δ λ ≈ 100 nm (bandwidth-length product of Δ λ · L ≈ 5 μ m²) near the telecom bands, and extraordinary adjustment flexibility.