Observation antibunching with classical light in a linear interferometer

TL;DR

This paper demonstrates that antibunching, a quantum phenomenon, can be observed using classical thermal light in a linear interferometer by employing photon-number-resolving detection, bridging classical and quantum optics.

Contribution

It shows that antibunching can be observed with classical thermal light through photon-number projection measurements in a Hanbury Brown-Twiss setup, revealing new insights into classical-quantum boundaries.

Findings

Antibunching observed with thermal light in a linear interferometer.

Photon-number projection measurements enable antibunching detection.

Comparison shows antibunching arises from photon statistics and measurement effects.

Abstract

Understanding the boundary between classical and nonclassical phenomena is important for both fundamental researches in quantum optics and applications in quantum information. One of the most interesting research directions in this field is exploring nonclassical effects with classical light. In this paper, we will show that it is possible to observe antibunching with thermal light in a Hanbury Brown-Twiss interferometer by treating single-photon detectors as photon-number-resolving detectors to perform photon-number projection measurements. Both temporal and spatial antibunching is observed via the correlation of two detectors detecting one and zero photon, respectively. By comparing the measured results of thermal and laser light, it is found that the observed antibunching arises from the combined effect of photon statistics of thermal light and photon-number projection measurement.The classical and nonclassical nature of the observed antibunching is analyzed. The results are helpful to understand the connection between classical and nonclassical correlation and may find applications in multiphoton interference and quantum imaging.