# Observation of two-photon interference effect with single non-photon-number resolving detector

## TL;DR

This paper demonstrates that two-photon interference, specifically the Hong-Ou-Mandel effect, can be observed using a single non-photon-number resolving detector through time-delayed coincidence measurements of successive signals.

## Contribution

It introduces a method to observe two-photon interference with a single non-photon-number resolving detector, simplifying experimental setups.

## Key findings

- Successful measurement of high-visibility Hong-Ou-Mandel interference fringes
- Use of temporally well-separated weak coherent pulses
- Validation of the method within the source's photon number limitations

## Abstract

Multiphoton interference effects can be measured with a single detector when two input photons are temporally well separated when compared with the dead time of the single-photon avalanche detector. Here we experimentally demonstrate that the Hong-Ou-Mandel interference effect can be observed with a single non-photon-number resolving detector via a time-delayed coincidence measurement of successive electrical signals from the detector. The two-photon interference experiment is performed by utilizing temporally well-separated pairwise weak coherent pulses and the interference fringes are successfully measured with a high visibility in the range of the limited upper bound for the weak coherent photon source.

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Source: https://tomesphere.com/paper/1706.03588