Usually, to understand a quantum state of light, you need to perform dozens of complex measurements, like trying all the keys on a keychain. The new AI model works differently: it's a universal key that, after a slight adjustment, opens many 'locks'—simple and the most tricky states. To do this, it only needs a rough estimate of intensity, photometry, instead of labor-intensive spectroscopy.

The model predicts how close the state is to ideal and whether it has unusual quantum properties — for example, negativity of the Wigner function, without which data teleportation is impossible. It's especially impressive that it even handles Schrödinger's cats (light oscillating in two opposite phases at once) and multi-beam squeezed states, where each beam is like a note in an orchestra, playing softer than a whisper but together producing a pure tone.

This key dramatically simplifies verification: for the largest optical quantum computer with a hundred beams, without the model, years of measurements would be needed — now it takes just minutes. This paves the way for accelerated development of quantum networks transmitting photons at the speed of light and ultra-precise sensors.