Two-photon interference with two independent and tunable single-mode continuous-wave lasers

TL;DR

This paper investigates the conditions under which second-order temporal interference occurs between two independent tunable lasers, combining theoretical analysis with experimental verification to enhance understanding of two-photon interference in quantum information.

Contribution

It provides a theoretical framework and experimental validation for two-photon interference between independent lasers with different spectra, clarifying the role of detection resolution.

Findings

Interference depends on detection time resolution and laser frequency difference

Experimental results match theoretical predictions

Insights into two-photon interference for quantum information applications

Abstract

The second-order temporal interference between two independent single-mode continuous-wave lasers is discussed by employing two-photon interference in Feynman's path integral theory. It is concluded that whether the second-order temporal interference pattern can be retrieved via two-photon coincidence counting measurement is dependent on the relationship between the resolution time of the detection system and the frequency difference between these two lasers. Two identical and tunable single-mode diode lasers are employed to verify the predictions experimentally. The experimental results are consistent with the theoretical predictions. These studies are helpful to understand the physics of two-photon interference with photons of different spectrums and application of two-photon interference in quantum information processing.