Mixing second and third-order nonlinear interactions in nanophotonic lithium-niobate waveguides

TL;DR

This paper explores how second and third-order nonlinearities interact in lithium-niobate waveguides, demonstrating how poling period design can precisely control output spectra for advanced photonic applications.

Contribution

It introduces a novel approach to tailor nonlinear interactions in lithium-niobate waveguides using engineered poling patterns and comprehensive pulse propagation modeling.

Findings

Poling period can be used to control sum- and difference-frequency generation.

Accurate modeling captures complex nonlinear interactions.

Tailored spectra achieved through poling design.

Abstract

In this paper, we have investigated the interplay between the second and third-order nonlinearities in lithium-niobate waveguides with strong waveguide dispersion using uniform and linearly-chirped poling patterns at input powers in the pico-joule range. We have implemented the accurate unidirectional pulse propagation model to take into account all the possible nonlinear interactions inside these structures. In particular, the poling period has been designed to quasi-phase-match single and multiple sum- and difference-frequency generation processes. We have shown how the poling period can be used as an additional degree of freedom to tailor the output spectra of chip-based nonlinear waveguides in an unprecedented way.