Quantum physicists can now distil a kind of photon schnapps. When spirits are distilled, the alcohol content increases relative to the water content. A similar method developed by a team from the Max Planck Institute of Quantum Optics in Garching works on light quanta – photons. It extracts individual photons from a light source, pushes back the unwanted vacuum component, and reports this event. Such single photons are important quantum bits for the currently emerging quantum information technology.
Source:
https://phys.org/news/2019-04-atom-cavity-highly-pure-photons.html