Research And Application Of Secure High-speed Optical Communication Technology Based On Quantum Noise Stream Cipher

As five-generation(5G)mobile communication continues to roll out,and the rise of services such as internet of things,cloud computing and cloud storage,global data traffic has exploded.However,endless optical fiber eavesdropping technologies and attack methods have brought serious security risks to optical fiber communications.Secure communication has gradually become the focus of attention.This thesis proposes a new type of physical layer encryption technology,that is,quantum noise stream cipher(QNSC),and applies it to two different communication scenarios.One is the medium and short distance high-speed intensity modulation and direct detection(IM/DD)system in the data center.Another is long-distance high-speed coherent optical communication system.These contents have certain guiding significance for the research of physical layer security encryption technology that meets the existing communication rate requirements.The main tasks and responsibilities are as discussed below:(1)In the IM/DD system,the optical coarse-to-fine modulation(CTFM)schemes based on optical coupler and polarization beam combiner are respectively proposed to improve the secure performance and transmission performance of the QNSC system.(2)A medium and short distance high-speed IM/DD optical fiber security communication platform based on the data center is proposed and experimentally demonstrated.Using quantum noise stream cipher technology,PAM4-QNSC signal transmission with a rate of 100Gb/s is realized.In order to suppress the influence of the power fading caused by the link dispersion,the system transmitter uses a dual-drive Mach-Zehnder modulator(DD-MZM)to modulate the signal with single sideband,which extends the transmission distance of the signal.In order to improve the safety performance of the system,the transmitter adopts two parallel DD-MZMs to realize the optical domain coarse-to-fine modulation of the QNSC signal,which overcomes the shortcomings of low signal-to-noise ratio of the fine modulation arm signal in the traditional coarse-to-fine modulation scheme.Finally,a secure 100Gb/s 2¹⁴ level PAM4-QNSC signal over50km standard single-mode fiber is achieved.(3)A long-distance high-speed coherent 16QAM-QNSC optical fiber security communication platform is proposed and experimentally demonstrated.In the case of using a high-linewidth laser(100k Hz),the BER performance difference between the use of the Volterra equalization algorithm and the RDA equalization algorithm to equalize the signal is analyzed.With the help of using the Volterra equalizer to perform the IQ signal to reduce the influence of phase noise on the signal decryption performance,finally the quantum noise stream cipher technology is used to realize the 16QAM-QNSC signal transmission 10km at a rate of 80Gb/s.