---
_id: '62269'
abstract:
- lang: eng
text: 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.
article_number: '50451'
article_type: original
author:
- first_name: Nina Amelie
full_name: Lange, Nina Amelie
id: '56843'
last_name: Lange
orcid: 0000-0001-6624-7098
- first_name: Sebastian
full_name: Lengeling, Sebastian
id: '44373'
last_name: Lengeling
- first_name: Philipp
full_name: Mues, Philipp
id: '49772'
last_name: Mues
orcid: 0000-0003-0643-7636
- first_name: Viktor
full_name: Quiring, Viktor
last_name: Quiring
- first_name: Werner
full_name: Ridder, Werner
id: '63574'
last_name: Ridder
- first_name: Christof
full_name: Eigner, Christof
id: '13244'
last_name: Eigner
orcid: https://orcid.org/0000-0002-5693-3083
- first_name: Harald
full_name: Herrmann, Harald
id: '216'
last_name: Herrmann
- first_name: Christine
full_name: Silberhorn, Christine
id: '26263'
last_name: Silberhorn
- first_name: Tim
full_name: Bartley, Tim
id: '49683'
last_name: Bartley
citation:
ama: Lange NA, Lengeling S, Mues P, et al. Widely non-degenerate nonlinear frequency
conversion in cryogenic titanium in-diffused lithium niobate waveguides. Optics
Express. 2025;33(24). doi:10.1364/oe.578108
apa: Lange, N. A., Lengeling, S., Mues, P., Quiring, V., Ridder, W., Eigner, C.,
Herrmann, H., Silberhorn, C., & Bartley, T. (2025). Widely non-degenerate
nonlinear frequency conversion in cryogenic titanium in-diffused lithium niobate
waveguides. Optics Express, 33(24), Article 50451. https://doi.org/10.1364/oe.578108
bibtex: '@article{Lange_Lengeling_Mues_Quiring_Ridder_Eigner_Herrmann_Silberhorn_Bartley_2025,
title={Widely non-degenerate nonlinear frequency conversion in cryogenic titanium
in-diffused lithium niobate waveguides}, volume={33}, DOI={10.1364/oe.578108},
number={2450451}, journal={Optics Express}, publisher={Optica Publishing Group},
author={Lange, Nina Amelie and Lengeling, Sebastian and Mues, Philipp and Quiring,
Viktor and Ridder, Werner and Eigner, Christof and Herrmann, Harald and Silberhorn,
Christine and Bartley, Tim}, year={2025} }'
chicago: Lange, Nina Amelie, Sebastian Lengeling, Philipp Mues, Viktor Quiring,
Werner Ridder, Christof Eigner, Harald Herrmann, Christine Silberhorn, and Tim
Bartley. “Widely Non-Degenerate Nonlinear Frequency Conversion in Cryogenic Titanium
in-Diffused Lithium Niobate Waveguides.” Optics Express 33, no. 24 (2025).
https://doi.org/10.1364/oe.578108.
ieee: 'N. A. Lange et al., “Widely non-degenerate nonlinear frequency conversion
in cryogenic titanium in-diffused lithium niobate waveguides,” Optics Express,
vol. 33, no. 24, Art. no. 50451, 2025, doi: 10.1364/oe.578108.'
mla: Lange, Nina Amelie, et al. “Widely Non-Degenerate Nonlinear Frequency Conversion
in Cryogenic Titanium in-Diffused Lithium Niobate Waveguides.” Optics Express,
vol. 33, no. 24, 50451, Optica Publishing Group, 2025, doi:10.1364/oe.578108.
short: N.A. Lange, S. Lengeling, P. Mues, V. Quiring, W. Ridder, C. Eigner, H. Herrmann,
C. Silberhorn, T. Bartley, Optics Express 33 (2025).
date_created: 2025-11-20T10:35:35Z
date_updated: 2025-12-12T12:13:45Z
department:
- _id: '15'
- _id: '623'
- _id: '288'
doi: 10.1364/oe.578108
intvolume: ' 33'
issue: '24'
language:
- iso: eng
main_file_link:
- open_access: '1'
oa: '1'
project:
- _id: '171'
name: 'TRR 142; TP C07: Hohlraum-verstärkte Parametrische Fluoreszenz mit zeitlicher
Filterung unter Verwendung integrierter supraleitender Detektoren'
publication: Optics Express
publication_identifier:
issn:
- 1094-4087
publication_status: published
publisher: Optica Publishing Group
status: public
title: Widely non-degenerate nonlinear frequency conversion in cryogenic titanium
in-diffused lithium niobate waveguides
type: journal_article
user_id: '49683'
volume: 33
year: '2025'
...
---
_id: '63091'
abstract:
- lang: eng
text: We present the design and characterization of a guided-wave, bright, and highly
frequency non-degenerate parametric down-conversion (PDC) source in thin-film
lithium niobate. The source generates photon pairs with wavelengths of 815 nm
and 1550 nm, linking the visible wavelength regime with telecommunication wavelengths.
We confirm the high quality of the generated single photons by determining a value
for the heralded second-order correlation function as low as g_h^(2)=(6.7+/-1.1)*10^8-3).
Furthermore, we achieve a high spectral brightness of 0.44·10pairs/(smWGHz) which
is two orders of magnitude higher than sources based on weakly guiding waveguides.
The shape of the PDC spectrum and the strong agreement between the effective and
nominal bandwidth highlight our high fabrication quality of periodically poled
waveguides. The good agreement between the measured and simulated spectral characteristics
of our source demonstrates our excellent understanding of the PDC process. Our
result is a valuable step towards practical and scalable quantum communication
networks as well as photonic quantum computing.
article_number: '52729'
article_type: original
author:
- first_name: Silia
full_name: Babel, Silia
id: '63231'
last_name: Babel
orcid: https://orcid.org/0000-0002-1568-2580
- first_name: Laura
full_name: Bollmers, Laura
id: '61375'
last_name: Bollmers
- first_name: Franz
full_name: Roeder, Franz
id: '88149'
last_name: Roeder
- first_name: Werner
full_name: Ridder, Werner
id: '63574'
last_name: Ridder
- first_name: Christian
full_name: Golla, Christian
id: '40420'
last_name: Golla
- first_name: Ronja
full_name: Köthemann, Ronja
last_name: Köthemann
- first_name: Bernhard
full_name: Reineke, Bernhard
id: '29821'
last_name: Reineke
- first_name: Harald
full_name: Herrmann, Harald
id: '216'
last_name: Herrmann
- first_name: Benjamin
full_name: Brecht, Benjamin
id: '27150'
last_name: Brecht
orcid: '0000-0003-4140-0556 '
- first_name: Christof
full_name: Eigner, Christof
id: '13244'
last_name: Eigner
orcid: https://orcid.org/0000-0002-5693-3083
- first_name: Laura
full_name: Padberg, Laura
id: '40300'
last_name: Padberg
- first_name: Christine
full_name: Silberhorn, Christine
id: '26263'
last_name: Silberhorn
citation:
ama: Babel S, Bollmers L, Roeder F, et al. Ultrabright, two-color photon pair source
based on thin-film lithium niobate for bridging visible and telecom wavelengths.
Optics Express. 2025;33(25). doi:10.1364/oe.571605
apa: Babel, S., Bollmers, L., Roeder, F., Ridder, W., Golla, C., Köthemann, R.,
Reineke, B., Herrmann, H., Brecht, B., Eigner, C., Padberg, L., & Silberhorn,
C. (2025). Ultrabright, two-color photon pair source based on thin-film lithium
niobate for bridging visible and telecom wavelengths. Optics Express, 33(25),
Article 52729. https://doi.org/10.1364/oe.571605
bibtex: '@article{Babel_Bollmers_Roeder_Ridder_Golla_Köthemann_Reineke_Herrmann_Brecht_Eigner_et
al._2025, title={Ultrabright, two-color photon pair source based on thin-film
lithium niobate for bridging visible and telecom wavelengths}, volume={33}, DOI={10.1364/oe.571605}, number={2552729},
journal={Optics Express}, publisher={Optica Publishing Group}, author={Babel,
Silia and Bollmers, Laura and Roeder, Franz and Ridder, Werner and Golla, Christian
and Köthemann, Ronja and Reineke, Bernhard and Herrmann, Harald and Brecht, Benjamin
and Eigner, Christof and et al.}, year={2025} }'
chicago: Babel, Silia, Laura Bollmers, Franz Roeder, Werner Ridder, Christian Golla,
Ronja Köthemann, Bernhard Reineke, et al. “Ultrabright, Two-Color Photon Pair
Source Based on Thin-Film Lithium Niobate for Bridging Visible and Telecom Wavelengths.”
Optics Express 33, no. 25 (2025). https://doi.org/10.1364/oe.571605.
ieee: 'S. Babel et al., “Ultrabright, two-color photon pair source based
on thin-film lithium niobate for bridging visible and telecom wavelengths,” Optics
Express, vol. 33, no. 25, Art. no. 52729, 2025, doi: 10.1364/oe.571605.'
mla: Babel, Silia, et al. “Ultrabright, Two-Color Photon Pair Source Based on Thin-Film
Lithium Niobate for Bridging Visible and Telecom Wavelengths.” Optics Express,
vol. 33, no. 25, 52729, Optica Publishing Group, 2025, doi:10.1364/oe.571605.
short: S. Babel, L. Bollmers, F. Roeder, W. Ridder, C. Golla, R. Köthemann, B. Reineke,
H. Herrmann, B. Brecht, C. Eigner, L. Padberg, C. Silberhorn, Optics Express 33
(2025).
date_created: 2025-12-15T07:20:36Z
date_updated: 2026-01-07T11:28:35Z
department:
- _id: '288'
- _id: '623'
doi: 10.1364/oe.571605
intvolume: ' 33'
issue: '25'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://opg.optica.org/oe/fulltext.cfm?uri=oe-33-25-52729
oa: '1'
publication: Optics Express
publication_identifier:
issn:
- 1094-4087
publication_status: published
publisher: Optica Publishing Group
status: public
title: Ultrabright, two-color photon pair source based on thin-film lithium niobate
for bridging visible and telecom wavelengths
type: journal_article
user_id: '63231'
volume: 33
year: '2025'
...
---
_id: '56267'
author:
- first_name: Laura
full_name: Serino, Laura
id: '88242'
last_name: Serino
- first_name: Werner
full_name: Ridder, Werner
id: '63574'
last_name: Ridder
- first_name: Abhinandan
full_name: Bhattacharjee, Abhinandan
id: '95902'
last_name: Bhattacharjee
- first_name: Jano
full_name: Gil López, Jano
id: '51223'
last_name: Gil López
- first_name: Benjamin
full_name: Brecht, Benjamin
id: '27150'
last_name: Brecht
orcid: '0000-0003-4140-0556 '
- first_name: Christine
full_name: Silberhorn, Christine
id: '26263'
last_name: Silberhorn
citation:
ama: 'Serino L, Ridder W, Bhattacharjee A, Gil López J, Brecht B, Silberhorn C.
Orchestrating time and color: a programmable source of high-dimensional entanglement.
Optica Quantum. Published online 2024. doi:10.1364/opticaq.532334'
apa: 'Serino, L., Ridder, W., Bhattacharjee, A., Gil López, J., Brecht, B., &
Silberhorn, C. (2024). Orchestrating time and color: a programmable source of
high-dimensional entanglement. Optica Quantum. https://doi.org/10.1364/opticaq.532334'
bibtex: '@article{Serino_Ridder_Bhattacharjee_Gil López_Brecht_Silberhorn_2024,
title={Orchestrating time and color: a programmable source of high-dimensional
entanglement}, DOI={10.1364/opticaq.532334},
journal={Optica Quantum}, publisher={Optica Publishing Group}, author={Serino,
Laura and Ridder, Werner and Bhattacharjee, Abhinandan and Gil López, Jano and
Brecht, Benjamin and Silberhorn, Christine}, year={2024} }'
chicago: 'Serino, Laura, Werner Ridder, Abhinandan Bhattacharjee, Jano Gil López,
Benjamin Brecht, and Christine Silberhorn. “Orchestrating Time and Color: A Programmable
Source of High-Dimensional Entanglement.” Optica Quantum, 2024. https://doi.org/10.1364/opticaq.532334.'
ieee: 'L. Serino, W. Ridder, A. Bhattacharjee, J. Gil López, B. Brecht, and C. Silberhorn,
“Orchestrating time and color: a programmable source of high-dimensional entanglement,”
Optica Quantum, 2024, doi: 10.1364/opticaq.532334.'
mla: 'Serino, Laura, et al. “Orchestrating Time and Color: A Programmable Source
of High-Dimensional Entanglement.” Optica Quantum, Optica Publishing Group,
2024, doi:10.1364/opticaq.532334.'
short: L. Serino, W. Ridder, A. Bhattacharjee, J. Gil López, B. Brecht, C. Silberhorn,
Optica Quantum (2024).
date_created: 2024-09-27T11:46:59Z
date_updated: 2025-12-01T08:49:46Z
department:
- _id: '288'
- _id: '623'
- _id: '288'
doi: 10.1364/opticaq.532334
language:
- iso: eng
project:
- _id: '211'
name: 'QuICHE: Quanteninformation und Quantenkommunikation mit hochdimensionaler
Informationskodierung (QuICHE)'
publication: Optica Quantum
publication_identifier:
issn:
- 2837-6714
publication_status: published
publisher: Optica Publishing Group
status: public
title: 'Orchestrating time and color: a programmable source of high-dimensional entanglement'
type: journal_article
user_id: '63574'
year: '2024'
...