---
_id: '63745'
abstract:
- lang: eng
text: Multimode squeezed light is an increasingly popular tool in photonic quantum
technologies, including sensing, imaging, and computation. Meanwhile, the existing
methods of its characterization are technically complicated, which reduces the
level of squeezing, and mostly deal with a single mode at a time. Here, for the
first time, to the best of our knowledge, we employ optical parametric amplification
to characterize multiple squeezing eigenmodes simultaneously. We retrieve the
shapes and squeezing degrees of all modes at once through direct detection followed
by modal decomposition. This method is tolerant to inefficient detection and does
not require a local oscillator. For a spectrally and spatially multimode squeezed
vacuum, we characterize eight strongest spatial modes, obtaining squeezing and
anti-squeezing values of up to −5.2 ± 0.2 dB and 8.6 ± 0.3 dB, respectively, despite
the 50% detection loss. This work, being the first exploration of an optical parametric
amplifier’s multimode capability for squeezing detection, paves the way for the
real-time detection of multimode squeezing.
article_number: '36'
article_type: original
author:
- first_name: Ismail
full_name: Barakat, Ismail
last_name: Barakat
- first_name: Mahmoud
full_name: Kalash, Mahmoud
last_name: Kalash
- first_name: Dennis
full_name: Scharwald, Dennis
id: '55907'
last_name: Scharwald
orcid: 0009-0007-5654-5412
- first_name: Polina
full_name: Sharapova, Polina
id: '60286'
last_name: Sharapova
- first_name: Norbert
full_name: Lindlein, Norbert
last_name: Lindlein
- first_name: Maria
full_name: Chekhova, Maria
last_name: Chekhova
citation:
ama: Barakat I, Kalash M, Scharwald D, Sharapova P, Lindlein N, Chekhova M. Simultaneous
measurement of multimode squeezing through multimode phase-sensitive amplification.
Optica Quantum. 2025;3(1). doi:10.1364/opticaq.524682
apa: Barakat, I., Kalash, M., Scharwald, D., Sharapova, P., Lindlein, N., &
Chekhova, M. (2025). Simultaneous measurement of multimode squeezing through multimode
phase-sensitive amplification. Optica Quantum, 3(1), Article 36.
https://doi.org/10.1364/opticaq.524682
bibtex: '@article{Barakat_Kalash_Scharwald_Sharapova_Lindlein_Chekhova_2025, title={Simultaneous
measurement of multimode squeezing through multimode phase-sensitive amplification},
volume={3}, DOI={10.1364/opticaq.524682},
number={136}, journal={Optica Quantum}, publisher={Optica Publishing Group}, author={Barakat,
Ismail and Kalash, Mahmoud and Scharwald, Dennis and Sharapova, Polina and Lindlein,
Norbert and Chekhova, Maria}, year={2025} }'
chicago: Barakat, Ismail, Mahmoud Kalash, Dennis Scharwald, Polina Sharapova, Norbert
Lindlein, and Maria Chekhova. “Simultaneous Measurement of Multimode Squeezing
through Multimode Phase-Sensitive Amplification.” Optica Quantum 3, no.
1 (2025). https://doi.org/10.1364/opticaq.524682.
ieee: 'I. Barakat, M. Kalash, D. Scharwald, P. Sharapova, N. Lindlein, and M. Chekhova,
“Simultaneous measurement of multimode squeezing through multimode phase-sensitive
amplification,” Optica Quantum, vol. 3, no. 1, Art. no. 36, 2025, doi:
10.1364/opticaq.524682.'
mla: Barakat, Ismail, et al. “Simultaneous Measurement of Multimode Squeezing through
Multimode Phase-Sensitive Amplification.” Optica Quantum, vol. 3, no. 1,
36, Optica Publishing Group, 2025, doi:10.1364/opticaq.524682.
short: I. Barakat, M. Kalash, D. Scharwald, P. Sharapova, N. Lindlein, M. Chekhova,
Optica Quantum 3 (2025).
date_created: 2026-01-26T15:57:13Z
date_updated: 2026-02-10T22:44:44Z
department:
- _id: '15'
- _id: '569'
- _id: '170'
- _id: '35'
- _id: '429'
doi: 10.1364/opticaq.524682
intvolume: ' 3'
issue: '1'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://opg.optica.org/opticaq/viewmedia.cfm?uri=opticaq-3-1-36&seq=0
oa: '1'
project:
- _id: '53'
name: 'TRR 142: Maßgeschneiderte nichtlineare Photonik: Von grundlegenden Konzepten
zu funktionellen Strukturen'
- _id: '56'
name: TRR 142 - Project Area C
- _id: '174'
name: 'TRR 142 ; TP: C10: Erzeugung und Charakterisierung von Quantenlicht in nichtlinearen
Systemen: Eine theoretische Analyse'
- _id: '52'
name: Computing Resources Provided by the Paderborn Center for Parallel Computing
publication: Optica Quantum
publication_identifier:
issn:
- 2837-6714
publication_status: published
publisher: Optica Publishing Group
status: public
title: Simultaneous measurement of multimode squeezing through multimode phase-sensitive
amplification
type: journal_article
user_id: '55907'
volume: 3
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'
...
---
_id: '50840'
abstract:
- lang: eng
text: Superconducting nanowire single-photon detectors (SNSPDs) have been
widely used to study the discrete nature of quantum states of light in the form
of photon-counting experiments. We show that SNSPDs can also be used to study
continuous variables of optical quantum states by performing homodyne detection
at a bandwidth of 400 kHz. By measuring the interference of a continuous-wave
field of a local oscillator with the field of the vacuum state using two SNSPDs,
we show that the variance of the difference in count rates is linearly proportional
to the photon flux of the local oscillator over almost five orders of magnitude.
The resulting shot-noise clearance of (46.0 ± 1.1) dB is the highest reported
clearance for a balanced optical homodyne detector, demonstrating their potential
for measuring highly squeezed states in the continuous-wave regime. In addition,
we measured a CMRR = 22.4 dB. From the joint click counting statistics, we also
measure the phase-dependent quadrature of a weak coherent state to demonstrate
our device’s functionality as a homodyne detector.
article_number: '1'
author:
- first_name: Maximilian
full_name: Protte, Maximilian
id: '46170'
last_name: Protte
- first_name: Timon
full_name: Schapeler, Timon
id: '55629'
last_name: Schapeler
orcid: 0000-0001-7652-1716
- first_name: Jan
full_name: Sperling, Jan
id: '75127'
last_name: Sperling
orcid: 0000-0002-5844-3205
- first_name: Tim
full_name: Bartley, Tim
id: '49683'
last_name: Bartley
citation:
ama: Protte M, Schapeler T, Sperling J, Bartley T. Low-noise balanced homodyne detection
with superconducting nanowire single-photon detectors. Optica Quantum.
2024;2(1). doi:10.1364/opticaq.502201
apa: Protte, M., Schapeler, T., Sperling, J., & Bartley, T. (2024). Low-noise
balanced homodyne detection with superconducting nanowire single-photon detectors.
Optica Quantum, 2(1), Article 1. https://doi.org/10.1364/opticaq.502201
bibtex: '@article{Protte_Schapeler_Sperling_Bartley_2024, title={Low-noise balanced
homodyne detection with superconducting nanowire single-photon detectors}, volume={2},
DOI={10.1364/opticaq.502201},
number={11}, journal={Optica Quantum}, publisher={Optica Publishing Group}, author={Protte,
Maximilian and Schapeler, Timon and Sperling, Jan and Bartley, Tim}, year={2024}
}'
chicago: Protte, Maximilian, Timon Schapeler, Jan Sperling, and Tim Bartley. “Low-Noise
Balanced Homodyne Detection with Superconducting Nanowire Single-Photon Detectors.”
Optica Quantum 2, no. 1 (2024). https://doi.org/10.1364/opticaq.502201.
ieee: 'M. Protte, T. Schapeler, J. Sperling, and T. Bartley, “Low-noise balanced
homodyne detection with superconducting nanowire single-photon detectors,” Optica
Quantum, vol. 2, no. 1, Art. no. 1, 2024, doi: 10.1364/opticaq.502201.'
mla: Protte, Maximilian, et al. “Low-Noise Balanced Homodyne Detection with Superconducting
Nanowire Single-Photon Detectors.” Optica Quantum, vol. 2, no. 1, 1, Optica
Publishing Group, 2024, doi:10.1364/opticaq.502201.
short: M. Protte, T. Schapeler, J. Sperling, T. Bartley, Optica Quantum 2 (2024).
date_created: 2024-01-25T11:48:02Z
date_updated: 2025-12-18T17:06:27Z
department:
- _id: '15'
- _id: '623'
doi: 10.1364/opticaq.502201
intvolume: ' 2'
issue: '1'
language:
- iso: eng
main_file_link:
- open_access: '1'
oa: '1'
project:
- _id: '191'
name: 'PhoQuant: Photonische Quantencomputer - Quantencomputing Testplattform'
- _id: '239'
name: 'ERC-Grant: QuESADILLA: Quantum Engineering Superconducting Array Detectors
in Low-Light Applications'
- _id: '209'
name: 'ISOQC: Quantenkommunikation mit integrierter Optik im Zusammenhang mit supraleitender
Elektronik'
publication: Optica Quantum
publication_identifier:
issn:
- 2837-6714
publication_status: published
publisher: Optica Publishing Group
status: public
title: Low-noise balanced homodyne detection with superconducting nanowire single-photon
detectors
type: journal_article
user_id: '55629'
volume: 2
year: '2024'
...