Forward spectral filtering parallel quantum key distribution system

A parallel quantum key distribution scheme, which allows the secret keys to be shared by polarization coding in parallel sidebands channel of different frequencies, is presented and studied on a theoretical basis. Theoretically speaking, the shared key generation rate could be increased several times. A forward spectral filtering structure for filtering the carrier frequency and other unwanted frequencies in the output pulse is designed and studied. The filtered pulse can be divided by receiver’s wavelength division demultiplexer. The simulation shows that an experimental implementation of this scheme is possible.