Observation of non-diffracting behavior at the single-photon level.

Area of Science:

• Quantum Optics and Photonics
• Single-Photon Sources
• Non-Diffracting Beams

Background:

• Single photons are crucial for quantum information processing.
• Maintaining photon properties like spatial distribution during propagation is challenging.
• Non-diffracting beams offer stable propagation characteristics.

Purpose of the Study:

• To generate single photons with non-diffracting properties.
• To leverage Bessel-Gauss beams for heralded single-photon generation.
• To demonstrate intrinsic non-diffracting behavior in heralded single photons.

Main Methods:

• Utilized spontaneous parametric downconversion (SPDC) to create photon pairs.
• Pumped the SPDC crystal with a Bessel-Gauss (BG) beam.
• Heralded single photons via the detection of their entangled idler photons.

Main Results:

• Successfully generated heralded single photons exhibiting non-diffracting transverse intensity distributions.
• The non-diffracting property of the Bessel-Gauss pump beam was directly mapped to the heralded single photons.
• The single-photon transverse amplitude did not require post-generation projection to achieve non-diffracting behavior.

Conclusions:

• Demonstrated a novel method for creating non-diffracting heralded single photons.
• This technique integrates non-diffracting beam properties directly into single-photon generation.
• Offers a pathway for robust single-photon propagation in quantum optical systems.