Pulse characterization at the single-photon level through chronocyclic Q-function measurements
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989592%3A15310%2F25%3A73628546" target="_blank" >RIV/61989592:15310/25:73628546 - isvavai.cz</a>
Result on the web
<a href="https://opg.optica.org/oe/fulltext.cfm?uri=oe-33-3-5551&id=567737" target="_blank" >https://opg.optica.org/oe/fulltext.cfm?uri=oe-33-3-5551&id=567737</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1364/OE.540125" target="_blank" >10.1364/OE.540125</a>
Alternative languages
Result language
angličtina
Original language name
Pulse characterization at the single-photon level through chronocyclic Q-function measurements
Original language description
The characterization of the complex spectral amplitude, that is, the spectrum and spectral phase, of single-photon-level light fields is a crucial capability for modern photonic quantum technologies. Since established pulse characterization techniques are not applicable at low intensities, alternative approaches are required. Here, we demonstrate the retrieval of the complex spectral amplitude of single-photon-level light pulses through measuring their chronocyclic Q −function. Our approach draws inspiration from quantum state tomography by exploiting the analogy between quadrature phase space and time-frequency phase space. In the experiment, we perform time-frequency projections with a quantum pulse gate (QPG), which directly yield the chronocyclic Q −function. We evaluate the complex spectral amplitude from the measured chronocyclic Q −function data with maximum likelihood estimation (MLE), which is the established technique for quantum state tomography. The MLE yields not only an unambigious estimate of the complex spectral amplitude of the state under test that does not require any a priori information, but also allows for, in principle, estimating the spectral-temporal coherence properties of the state. Our method accurately recovers features such as jumps in the spectral phase and is resistant against regions with zero spectral intensity, which makes it immediately beneficial for classical pulse characterization problems.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10306 - Optics (including laser optics and quantum optics)
Result continuities
Project
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Continuities
R - Projekt Ramcoveho programu EK
Others
Publication year
2025
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
OPTICS EXPRESS
ISSN
1094-4087
e-ISSN
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Volume of the periodical
33
Issue of the periodical within the volume
3
Country of publishing house
US - UNITED STATES
Number of pages
11
Pages from-to
5551-5561
UT code for WoS article
001524236900006
EID of the result in the Scopus database
2-s2.0-85217965975