Selective filtering of multi-photon events from a single-photon emitter

Area of Science:

• Quantum Optics
• Quantum Information Science

Background:

• Single-photon purity is crucial for quantum technologies.
• Multi-photon errors limit the purity of current single-photon sources.
• Spontaneous emission and re-excitation are primary limitations.

Purpose of the Study:

• To overcome fundamental limits in single-photon purity.
• To suppress multi-photon error rates in quantum sources.
• To enhance the fidelity of quantum states of light.

Main Methods:

• Utilizing distinct spectro-temporal properties of emitted photons.
• Employing narrowband spectral filters to isolate photons.
• Analyzing the degree of second-order coherence at zero time delay.

Main Results:

• Demonstrated overcoming fundamental limits to single-photon purity.
• Showcased filtering of instantaneously emitted photons using spectral filters.
• Reduced the degree of second-order coherence by nearly one order of magnitude.
• Achieved significant suppression of multi-photon error rates.

Conclusions:

• Distinct spectro-temporal photon properties can be leveraged to improve purity.
• Narrowband spectral filtering effectively reduces multi-photon errors.
• This technique enhances single-photon sources without compromising desired emission.