Ghost Diffraction in Time Domain: Two-Photon Reciprocal Two-Slit Diffraction-Interference

TL;DR

This paper demonstrates temporal ghost diffraction using two-photon cross-correlation with classical light, revealing interference fringes in the frequency-time domain that resemble quantum two-photon effects.

Contribution

It introduces a novel experimental setup for observing temporal ghost diffraction with classical light, bridging classical and quantum interference phenomena.

Findings

Clear spectral fringes with sinc-shaped visibility are observed.

Temporal ghost diffraction fringes develop with classical light sources.

The results confirm two-photon interference effects in the time domain.

Abstract

Temporal ghost diffraction (TGD) is observed by taking two-photon cross-correlation in the configuration of reciprocal two-slit diffraction (2SD) where interference fringes develop on the light source side as opposed to the detector side. To this end, a narrow-band chaotic light source and a gated detector are used in the frequency-time domain, which emulate a randomly pointing incoherent light source and a stationary pinhole detector in the momentum-space domain, respectively. Spectral fringes with visibility that closely follows a sinc function of spectral bandwidth are clear evidence that legitimate TGD fringes due to two-photon interference develop even with classical light.