Quantum properties of multimode light observed despite extreme losses

Quantum properties of light are extremely delicate.

When researchers attempt to measure them, even small losses on the way to a detector can make them invisible, limiting their use outside carefully controlled environments.

A collaborative team of researchers involving scientists at the Max Planck Institute for the Science of Light (MPL) has shown a new way to measure several quantum channels of light at the same time and reveal their entanglement, even when almost all of the light is lost before reaching the detector.

The results, recently published in Nature Communications, open new possibilities for scalable quantum technologies. ...