Ultrafast squeezed light tames quantum uncertainty in real time

Researchers at the University of Arizona, led by Mohammed Hassan, have achieved the first real-time measurement and control of quantum uncertainty using ultrafast squeezed light pulses. This breakthrough directly observes Heisenberg’s uncertainty principle in action by manipulating “squeezed light,” a quantum state where uncertainty is redistributed between two linked properties of photons—intensity and phase—allowing one property to be measured more precisely at the expense of the other. Unlike previous methods that used millisecond laser pulses, Hassan’s team generated squeezed light with femtosecond (one quadrillionth of a second) pulses via a novel four-wave mixing technique in fused silica, enabling ultrafast quantum optics. The team demonstrated real-time control over quantum uncertainty by adjusting the position of the silica relative to the laser beams, fluctuating between intensity and phase squeezing. This advancement not only opens a new field combining ultrafast lasers and quantum optics but also has practical implications for secure quantum communication. Their method enhances security by making it