Scientists can now 'see' the flickering quantum noise of light at a speed of a billionth of a billionth of a second.
April 17, 2026
Original Paper
Attosecond Access to the Quantum Noise of Light
arXiv · 2604.13485
The Takeaway
Light is not a steady stream; it has tiny, random hiccups caused by quantum fluctuations. These researchers used attosecond streaking to finally capture these fluctuations as they happen in real-time. It is like being able to see every individual spark in a fire that looks like a steady glow to everyone else. This gives us unprecedented control over squeezed light, which is the key to making gravitational wave detectors and quantum computers more powerful. It is the ultimate high-speed camera for the quantum world.
From the abstract
Characterizing the quantum state of intense light fields on sub-cycle timescales remains beyond the reach of existing methods. Here, we show that attosecond streaking provides direct, phase-sensitive access to the quantum properties of the driving field through delay-resolved photoelectron spectra. Using a Feynman--Vernon treatment, we decompose the influence of the quantized driving field on the photoelectron into coherent and fluctuation contributions. This yields a simple, moment-based charac