Highly efficient broadband second harmonic generation mediated by mode hybridization and nonlinearity patterning in compact fiber-integrated lithium niobate nano-waveguides.

ABSTRACT: The inherent trade-off between efficiency and bandwidth of three-wave mixing processes in ?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 ?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 ?nor???460% W-1 cm-2, combined with a large phase matching bandwidth of ?????100?nm (bandwidth-length product of ?? · L???5??m2) near the telecom bands, and extraordinary adjustment flexibility.

SUBMITTER: Cai L 

PROVIDER: S-EPMC6102234 | biostudies-other | 2018 Aug

REPOSITORIES: biostudies-other