Emulation of up-conversion based quantum key distribution scheme using active pump-controlled basis selection and adaptive thresholding

Abstract

We emulate a method for quantum key distribution (QKD) that employs up-conversion detection. The scheme uses differential quadrature phase shift modulation and actively chooses the measurement basis by applying a dynamic phase-shift on the pump of the up-conversion interaction. The QKD rate of the quantum-hacking resistant system over an emulated 7.5 km marine-like turbulent channel is evaluated including the impact of thresholding the received data so as to ignore signals that are below a tolerable signal-to-noise ratio. The emulated system is well suited to operate over marine free space optical links coupled to single mode fiber.