Ultrafast laser systems developed by Chromacity

The generation and detection of quantum states of light, particularly through entangled photons, is a critical focus in the development of next-generation secure communications for both guided wave and free-space systems. However, up until now, secure long-distance quantum-enhanced communications via satellites have been largely limited to nighttime operations, due to interference from background solar radiation during daylight hours.

A breakthrough by an international team of researchers, led by the University of Glasgow’s James Watt School of Engineering, has addressed this limitation. The team has developed a novel non-linear crystal composed of lithium niobate. By directing short light pulses from a Chromacity 1040 laser system through this crystal, the researchers have found a new way to generate entangled photons at a wavelength of 2.1 µm, further into the infrared spectrum. This advancement overcomes the issue of solar radiation, enabling secure quantum-based optical communication during the day for the first time.

Julian Hayes, CEO of Chromacity said: "Two of our ultrafast laser systems have been involved in this exciting research. Our Chromacity 1040 is the workhorse that allows the generation of entangled photons at 2.1 µm, while our Chromacity Auskerry OPO has been used as a tool to help push the development of single photon detectors used to detect the entangled photons. We are thrilled to see how a mix of our technologies is clearly having a real impact on important innovative research."

The research, titled ‘Two-photon Quantum Interference and Entanglement at 2.1 μm’, conducted by the University of Glasgow, is published in Science Advances.