# Detection-device-independent verification of nonclassical light

## TL;DR

This paper introduces detector-independent criteria for verifying nonclassical light using multiplexed detection, enabling robust certification even with imperfect detectors and complex photon sources.

## Contribution

It develops general nonclassicality criteria applicable to imperfect multiplexed detection setups without requiring detector calibration.

## Key findings

- Criteria successfully certify nonclassicality in experiments with single-photon emitters
- Method works with unbalanced multiplexing and excess photon numbers
- High statistical significance achieved in experimental verification

## Abstract

The efficient certification of nonclassical effects of light forms the basis for applications in optical quantum technologies. We derive general correlation conditions for the verification of nonclassical light based on multiplexed detection. The obtained nonclassicality criteria are valid for imperfectly-balanced multiplexing scenarios with on-off detectors and do not require any knowledge about the detector system. In this sense they are fully independent of the detector system. In our experiment, we study light emitted by clusters of single-photon emitters, whose photon number may exceed the number of detection channels. Even under such conditions, our criteria certify nonclassicality with high statistical significance.