The interference of independent light beams

Wolfgang Radloff

Leonid A. Vainshtein, V.N. Melekhin, S. A. Mishin +1 more

Jianbin Liu, Jingjing Wang, Zhuo Xu

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 the 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 an asymmetrical beam splitter is employed.

Bin Bai, Jianbin Liu, Songlin Zhang +4 more

By analyzing the transient first-order interference of two independent thermal light beams in both classical and quantum theories, we conclude that for a certain kind of thermal light, it is impossible to observe the transient first-order interference pattern by superposing two independent thermal light beams even if the degeneracy parameter of thermal light is much greater than one. The result suggests that the well-accepted classical model of a thermal light field within the coherence time is not valid for all kinds of thermal light, which is important and helpful to understand the first-order interference of thermal light.

Jianbin Liu, Mingnan Le, Bin Bai +2 more

By analyzing the first-order interference of two independent thermal light beams in Feynman's path integral theory, we conclude that it is impossible to observe the transient first-order interference pattern by superposing two independent thermal light beams if the initial phases of the photons in thermal light are random. The result suggests that the classical model of thermal light field within the coherence time may not be the same as the one of laser light field within the coherence time.

Lajos Jánossy, Zs. Náray