Quantum key distribution (QKD) is an emerging communication technology that utilizes quantum mechanics principles to ensure highly secure communication between two parties. It enables the sender and receiver to generate a shared secret key over a channel that may be monitored by an attacker. Any attempt to eavesdrop introduces detectable errors in the quantum signals, allowing communicating parties to detect if communication is compromised via QKD protocols.
Among the various parameters that influence the performance of QKD systems, pointing error, a misalignment between the transmitter and receiver, is one of the most important. Such misalignment can arise from mechanical vibrations, atmospheric turbulence, and/or inaccuracies in the alignment mechanisms.
Despite its importance, very few studies have examined pointing error in a comprehensive manner for QKD optical wireless communication (OWC) systems.








