Tello Castillo A, Zanforlin U, Buller G, Donaldson R. “Multiprotocol quantum key distribution receiver for free space”, Proceedings Volume 12335, Quantum Technology: Driving Commercialisation of an Enabling Science III; 123350B, 2023. DOI: 10.1117/12.2646456
Quantum Key Distribution (QKD), a technology for growing mathematically secure key encryption keys, is now on the verge of becoming widely commercially available. Due to lack of standardization, multiprotocol QKD receivers are particularly beneficial for satellite QKD, so that an optical ground station is not limited to a sub-set of satellites. Moreover, if both transmitter and receiver can operate with different protocols, they will be able to actively adapt to specific conditions by choosing the most suitable protocol. In this work, we present the design and performance of a multiprotocol reconfigurable free-space QKD receiver. The reconfigurability relies on polarization-based optical routing, which can also be used to optimize the performance of time-bin QKD protocols.