High Visibility Two-photon Interference with Classical Light

TL;DR

This paper demonstrates that using a random-phase grating to modulate classical coherent light can surpass the traditional 50% visibility limit in two-photon interference, highlighting phase control's role in high-order coherence.

Contribution

The study introduces a novel method employing a random-phase grating to enhance two-photon interference visibility beyond 50% with classical light.

Findings

Visibility exceeds 50% in two-photon interference with classical light.

Superposition of multiple indistinguishable two-photon paths enhances interference.

Phase control is crucial for high-order coherence in classical optics.

Abstract

Two-photon interference with independent classical sources, in which superposition of two indistinguishable two-photon paths plays a key role, is of limited visibility of interference fringes with a maximum value of 50%. By using a random-phase grating to modulate the wavefront of a coherent light, we introduce superposition of multiple indistinguishable two-photon paths, which enhances the two-photon interference effect with a signature of visibility exceeding 50%. The result shows the importance of phase control in the control of high-order coherence of classical light.