Three-Wave Mixing as a High-Throughput Diagnostic Tool for Nonlinear Waveguides
Abstract
The recent development of wavelength-scale nonlinear waveguides highlights the need for new diagnostic methods that characterize both waveguide dispersion and fabrication-induced spatial inhomogeneities. While tightly confining waveguides enable compact and highly efficient nonlinear devices, nanometer-scale waveguide nonuniformities can limit the effective interaction length and conversion efficiency. In this work, we establish a high-throughput diagnostic method for second-order nonlinear waveguides based on near-degenerate three-wave mixing, hereafter referred to as sum-frequency tomography (SFT). In contrast with conventional diagnostics based on second-harmonic generation, SFT produces two-dimensional transfer functions that allow dispersion orders to be characterized separately from longitudinal phase-mismatch variations. We validate this technique using commercially available PPLN waveguides and show that SFT recovers the group-velocity mismatch between the interacting waves, the group-velocity dispersion of the fundamental, and a low-order polynomial approximation of the longitudinal phase-mismatch profile. SFT avoids the experimental complexities of phase-sensitive or spatially resolved measurements, enabling the characterization of individual waveguides in seconds.
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BibTeX
@misc{liu2026threewave,
title = {{Three-Wave Mixing as a High-Throughput Diagnostic Tool for Nonlinear Waveguides}},
author = {Yi-Yang Liu and Kevin Chen and Kyungduk Kim and Ryotatsu Yanagimoto and Edwin Ng and Timothy P. McKenna and Marc Jankowski},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.00747},
eprint = {2610.00747},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.00747},
}
RIS
TY - UNPB
TI - Three-Wave Mixing as a High-Throughput Diagnostic Tool for Nonlinear Waveguides
AU - Yi-Yang Liu
AU - Kevin Chen
AU - Kyungduk Kim
AU - Ryotatsu Yanagimoto
AU - Edwin Ng
AU - Timothy P. McKenna
AU - Marc Jankowski
PY - 2026
DA - 2026/10/01
PB - arXiv
DO - 10.48550/arxiv.2610.00747
UR - https://arxiv.org/abs/2610.00747
AB - The recent development of wavelength-scale nonlinear waveguides highlights the need for new diagnostic methods that characterize both waveguide dispersion and fabrication-induced spatial inhomogeneities. While tightly confining waveguides enable compact and highly efficient nonlinear devices, nanometer-scale waveguide nonuniformities can limit the effective interaction length and conversion efficiency. In this work, we establish a high-throughput diagnostic method for second-order nonlinear waveguides based on near-degenerate three-wave mixing, hereafter referred to as sum-frequency tomography (SFT). In contrast with conventional diagnostics based on second-harmonic generation, SFT produces two-dimensional transfer functions that allow dispersion orders to be characterized separately from longitudinal phase-mismatch variations. We validate this technique using commercially available PPLN waveguides and show that SFT recovers the group-velocity mismatch between the interacting waves, the group-velocity dispersion of the fundamental, and a low-order polynomial approximation of the longitudinal phase-mismatch profile. SFT avoids the experimental complexities of phase-sensitive or spatially resolved measurements, enabling the characterization of individual waveguides in seconds.
ER -