Second-order temporal interference of two independent light beams at an asymmetrical beam splitter

TL;DR

This paper analyzes second-order temporal interference of classical and nonclassical light at an asymmetrical beam splitter using Feynman's path integral theory, highlighting how properties and beam splitter reflectivity affect interference visibility.

Contribution

It provides a theoretical framework for understanding how asymmetrical beam splitters influence second-order interference, especially for nonclassical light, with specific conditions for visibility enhancement.

Findings

Interference visibility depends on light properties, intensity ratio, and beam splitter reflectivity.

Visibility of nonclassical light interference can surpass classical limits under certain conditions.

Photon sources' emission independence makes interference visibility unaffected by intensity ratios.

Abstract

The second-order temporal interference of classical and nonclassical light at an asymmetrical beam splitter is discussed based on two-photon interference in Feynman's path integral theory. The visibility of the second-order interference pattern is determined by the properties of the superposed light beams, the ratio between the intensities of these two light beams, and the reflectivity of the asymmetrical beam splitter. Some requirements about the asymmetrical beam splitter have to be satisfied in order to ensure that the visibility of the second-order interference pattern of nonclassical light beams exceeds classical limit. The visibility of the second-order interference pattern of photons emitted by two independent single-photon sources is independent of the ratio between the intensities. These conclusions are important for the researches and applications in quantum optics and quantum information when asymmetrical beam splitter is employed.