Two-photon Interference with Non-identical Photons

TL;DR

This paper explores how the indistinguishability of non-identical photons affects two-photon interference in a Hong-Ou-Mandel setup, emphasizing the role of detection systems and light properties.

Contribution

It clarifies the conditions under which non-identical photons can produce interference, highlighting differences between classical and quantum light phenomena.

Findings

Indistinguishability depends on detection system properties.

Two-photon interference can occur with non-identical photons under certain conditions.

Differences between classical and quantum light interference are due to light and detection properties.

Abstract

The indistinguishability of non-identical photons is dependent on detection system in quantum physics. If two photons with different wavelengths are indistinguishable for a detection system, there can be two-photon interference when these two photons are incident to two input ports of a Hong-Ou-Mandel interferometer, respectively. The reason why two-photon interference phenomena are different for classical and nonclassical light is not due to interference, but due to the properties of light and detection system. These conclusions are helpful to understand the physics and applications of two-photon interference.