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Updated: Aug 1, 2026
09:23
Quantum State Engineering of Light with Continuous-wave Optical Parametric Oscillators
Published on: May 30, 2014
Quantum beat of two single photons.
Thomas Legero1, Tatjana Wilk, Markus Hennrich
1Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, D-85748 Garching, Germany.
Physical Review Letters
|August 25, 2004
Summary
Quantum interference of single photons was time-resolved. A quantum beat near 100% visibility was observed, demonstrating perfect two-photon coalescence is achievable even with imperfect photons using temporal filtering.
Area of Science:
- Quantum optics
- Atomic physics
- Photonics
Background:
- Quantum interference is a fundamental phenomenon.
- Understanding photon coherence is crucial for quantum technologies.
- Atom-cavity systems provide controlled sources of single photons.
Purpose of the Study:
- To measure the time-resolved interference of two single photons.
- To investigate quantum beats in photon correlations.
- To demonstrate perfect two-photon coalescence using temporal filtering.
Main Methods:
- Utilizing single photons from an atom-cavity system with different frequencies.
- Performing time-resolved measurements of photodetections at beam splitter output ports.
- Analyzing the correlation between photodetections to observe quantum beats.
Main Results:
- Observed a quantum beat with near 100% visibility in photon correlations.
- The time dependence of the beat amplitude revealed photon coherence properties.
- Found that simultaneous photodetections never occurred, enabling perfect coalescence with temporal filtering.
Conclusions:
- Time-resolved measurement reveals quantum beat visibility close to 100%.
- Photon coherence properties directly influence the beat amplitude's time dependence.
- Perfect two-photon coalescence can be achieved even for imperfect photons via temporal filtering.
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