Widely non-degenerate nonlinear frequency conversion in cryogenic titanium in-diffused lithium niobate waveguides
Abstract
The titanium in-diffused lithium niobate waveguide platform is well-established for reliable prototyping and packaging of many quantum photonic components at room temperature. Nevertheless, compatibility with certain quantum light sources and superconducting detectors requires operation under cryogenic conditions. We characterize alterations in phase-matching and mode guiding of a non-degenerate spontaneous parametric down-conversion process emitting around 1556 nm and 950 nm, under cryogenic conditions. Despite the effects of pyroelectricity and photorefraction, the spectral properties match our theoretical model. Nevertheless, these effects cause small but significant variations within and between cooling cycles. These measurements provide a first benchmark against which other nonlinear photonic integration platforms, such as thin-film lithium niobate, can be compared.
Keywords
Cite
@article{arxiv.2509.02392,
title = {Widely non-degenerate nonlinear frequency conversion in cryogenic titanium in-diffused lithium niobate waveguides},
author = {Nina Amelie Lange and Sebastian Lengeling and Philipp Mues and Viktor Quiring and Werner Ridder and Christof Eigner and Harald Herrmann and Christine Silberhorn and Tim J. Bartley},
journal= {arXiv preprint arXiv:2509.02392},
year = {2025}
}
Comments
18 pages, 7 figures