Light Waves Like Never Before: Scientists Unveil Groundbreaking Optical Quantum Detection

Researchers at Paderborn University have used a new method to determine the characteristics of optical, i.e. light-based, quantum states. For the first time, they are using certain photon detectors – devices that can detect individual light particles – for so-called homodyne detection.

The ability to characterize optical quantum states makes the method an essential tool for quantum information processing. Precise knowledge of the characteristics is important for use in quantum computers, for example. The results have now been published in the specialist journal Optica Quantum.

“Homodyne detection is a method frequently used in quantum optics to investigate the wave-like nature of optical quantum states,” explains Timon Schapeler from the Paderborn Mesoscopic Quantum Optics working group at the Department of Physics. Together with Dr Maximilian Protte, he has used the method to investigate the so-called continuous variables of optical quantum states. This involves the variable properties of light waves. These can be, for example, the amplitude or phase, i.e. the oscillation behavior of waves, which are important for the targeted manipulation of light, among other things.