Quantum Entanglement for Space-to-Earth Communications
Quantum Entanglement is an encryption technique that relies on Quantum Key Distribution (QKD) rather than traditional computer-based cryptography. Until now it was only thought possible to entangle photons at near-infrared (NIR) frequencies (0.7 µm – 1.5 µm). These NIR frequencies are very susceptible to atmospheric attenuation as well as background solar radiation. This limits the Satellite-to-earth communication window to strictly night time . Therefore, these wavelengths prove inefficient when urgent messages need to be sent but cannot because of the time of day.
A research group led by Dr. Matteo Clerici, from the University of Glasgow, were able to entangle photons at 2.1 µm wavelengths . This wavelength falls into Earth’s atmospheric transparency window, which is a region of the electromagnetic spectrum that experiences very little absorption by gasses in Earth’s atmosphere . This permits for Satellite-to-Earth communication during day or night time since less data is lost to solar radiation as well as atmospheric attenuation.