Physicists from Heriot-Watt University have proposed a breakthrough approach to mitigate "daylight noise," a significant barrier to creating a global quantum communication network. 

Current satellite quantum key distribution (SatQKD) systems operate only at night due to interference from sunlight, limiting their connectivity. The new method introduces “time and phase” encoding, allowing SatQKD to function during dawn and dusk, significantly extending operations by three to four hours daily.

Time and phase encoding, combined with polarisation filtering, reduces detected daylight noise. Early simulations show that this approach effectively filters daylight noise, enabling secure quantum communications even at dawn and dusk.