Mohammed Th. Hassan

⚛️ Scientists just bent the rules of quantum physics! Scientists have successfully captured and controlled quantum uncertainty in real time using incredibly fast pulses of light, opening the door to a new field called ultrafast quantum optics. Led by researchers from the University of Arizona, the study shows how “squeezed light”, a special kind of light where one property becomes more precise while another gets noisier, can now be generated and measured using laser pulses lasting just femtoseconds (or one quadrillionth of a second). In quantum physics, certain properties of particles, like light's intensity and phase, are linked in a way that makes it impossible to measure both perfectly at the same time, a concept called uncertainty. Normally, this uncertainty is balanced, like air evenly filling a round balloon. But with squeezed light, that “balloon” stretches into an oval, making one side (or one property) clearer while the other becomes fuzzier. Until now, squeezed light has only been used in slow applications, like gravitational-wave detection, with light pulses lasting milliseconds. The team behind the breakthrough figured out how to generate ultrafast squeezed light using a process called four-wave mixing. They split a laser into three identical beams and focused them into a piece of glass, which mixed the beams and produced squeezed light in ultrafast pulses. By changing the angle of the glass slightly, they could control which property, intensity or phase, was being squeezed. This is the first time anyone has both created and manipulated quantum uncertainty at such fast speeds. The technique has huge potential for secure communication. Source: Sainte-Marie, M. et al. (2025). Ultrafast Generation and Control of Squeezed Light via Four-Wave Mixing. Nature Photonics.