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arXiv · 2311.14399

Efficient and robust second-harmonic generation in thin-film lithium niobate using modal phase matching

Mikkel T. Hansen·Emil Z. Ulsig·Fabien Labbe·Magnus L. Madsen·Yunhong Ding·Karsten Rottwitt·Nicolas Volet
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Abstract

A double-ridge waveguide is designed for efficient and robust second-harmonic generation (SHG) using the thin-film lithium-niobate-on-insulator (LNOI) platform. Perfect phase matching (PhM) is achieved between the fundamental waveguide mode at 1550 nm and a higher-order mode at the second harmonic. The fabrication tolerances of the PhM condition are simulated using a finite-difference method mode solver, and conversion efficiencies as high as 3.92/W are obtained for a 1-cm long waveguide. This design allows access to the largest element of the second-order nonlinear susceptibility tensor, and represents a scalable alternative to waveguides based on periodically-poled lithium niobate (PPLN). The design has the potential for generating pairs of entangled photons in the infrared C-band by spontaneous parametric down-conversion (SPDC).

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Mikkel T. Hansen, Emil Z. Ulsig, Fabien Labbe, Magnus L. Madsen, Yunhong Ding, Karsten Rottwitt, Nicolas Volet. 2023-11-24. Efficient and robust second-harmonic generation in thin-film lithium niobate using modal phase matching. https://doi.org/10.3389/fphot.2023.1324648

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