Dual-channel all-optical encryption using hybrid modulation format XOR gates based on FWM in HNLF

An all-optical encryption/decryption scheme for 10-Gbaud quadrature phase shift keying (QPSK) and binary phase shift keying (BPSK) signals based on hybrid modulation formats exclusive-or (HMF-XOR) gates is proposed. Both theoretical analysis and simulation results are conducted to evaluate the feasibility of optical encryption/decryption scheme. The received OSNR penalties of decrypted QPSK and BPSK signals at BER of 10~
³
are 1dB and 0.7dB, respectively, the concentrated constellations and clear eye-diagrams indicate the high performance of decrypted signals.