Quantum communications system having pulses divided into time bins and associated methods

A quantum communications system comprising:

• a communications system;
• and
• a quantum key distribution (QKD) system operable with the communications system and comprising
• a transmitter node, a receiver node, and a quantum communications channel coupling the transmitter node and receiver node,
• the transmitter node comprising a pulse transmitter and a pulse divider downstream therefrom, the pulse divider configured to divide each pulse having a plurality of X photons into a plurality of Y time bins with Y>X, and
• the receiver node comprising a pulse recombiner and a pulse receiver downstream therefrom, wherein the pulse divider comprises a first plurality of staged birefringent crystals;
• and wherein the pulse recombiner comprises a second plurality of staged birefringent crystals.