Time-Bin Superposition Methods for DPS-QKD

Key generation efficiency, and security, in DPS-QKD improve with an increase the number of path delays or time-bin superpositions. We demonstrate implementation super-position states using time-bins, establish equivalence path-based superposition, thus yielding a simpler higher-order superposition for differential phase-shift quantum key distribution (DPS-QKD). set up DPS-QKD, over 105 km single mode optical fiber, bit error rate less than 15% at secure 2 kbps. With temporal guard bands, QBER reduced to 10%, but 20% reduction rate.