Research On The Key Technology And The Application Of High-speed Secure Optical Fiber Communication

Optical fiber communication is an important part of modern communication system.The security of optical fiber communication is seriously threantened by the endless incidents of optical fiber eavesdropping and the rapid development of the eavesdropping technology.The information security of optical fiber communication has become the most concerned problem.The information security technology based on the traditional encryption algorithm is increasingly weak and cannot be guaranteed with the improvement of the computing power.The optical fiber physical layer protection technology can realize the information security on the physical layer of optical signal through the physical characteristics of optical devices and the optical signal processing method.However,with the advent of the 5G era,the bit rate of the transmission in the data center has been upgraded from 100Gb/s to 400Gb/s.Most of the existing secure communication systems are unable to cope with the new communication requirements,and their security performance is still restricted by the communication rate.Therefore,it is urgent to study the key technology of high speed optical fiber secure communication system and realize high speed secure optical fiber communication.In this paper,considering the constraints of transmission performance and security performance,three kinds of secure communication schemes in different commucniation scenarios have been proposed.What's more,the transmission performance and security performance of the designed secure communication system have been explored and demonstrated.The main content and results are as follows:(1)A secure optical fiber communication system based on all-optical multi-domain transformation is proposed.By constructing random phase masking and optical transformation module,the signal is encrypted in multiple information domains,achieving secure transmission in the high-speed data channel.The encryption effect of two encryption mechanisms and the communication performance of the system are simulated and discussed.The results shows that the signal can be prosscessed in all-otpcal domain with transparent modulation formats and communication rate,and the transmission distrance can be extended to 1000km.The probability of the encrypted signal being successfully intercepted by eavesdropper is less than 0.004275%.A secure transmission of 4×10Gb/s signal over 200km standard single mode fiber(SSMF)is experimentally demonstrated.The achieved BER is lower than 10^-9,and the optical power penalty induced by the encrypted mechanism is 0.4db.(2)A>100Gb/s optical fiber communication system based on intensity shift keying quantum noise stream cipher(ISK-QNSC)is proposed.Based on ISK-QNSC technology,the security performance of the data channel is guaranteed.A DD-MZM is utilized to realize a single sideband modulation and eliminate the power fading caused by fiber dispersion.A novel sparse RLS-Volterra equalizer is proposed,which successfully eliminates the linear and nonlinear distortion of the transmission system.Furthermore,the structure of the proposed equalizer is greatly simplified and thus more>71%complexity reduction of the equalizer is realized on the premise of ensuring the communication performance.Finally,a secure transmission of 100Gb/s PAM4 signal over 100km SSMF and 150Gb/s PAM8 signal over 50km SSMF based on ISK-QNSC technology is realized for the first time.The achieved BER is lower than 3.8×10^-3,and the detection failure probabilities(DFP)of 98.72%in PAM4-QNSC transmission and 97.01%in PAM8-QNSC transmission for the eavesdropper are obtained.The optical power penalty induced by the ISK-QNSC operation is less than 0.7db.(3)A high-speed stable secure optical stealthy transmission communication system based on ASE noise is proposed,which utilizes the ASE noise to hide signal.The influence of different bandwidth of the ASE noise on system performance has been invesgated and anlyzed.The well-designed system is immune to the fluctuation of the polarization and time delay caused by environmental variation,enhancing the system stability.And there is no need for key distribution since the only Mach-Zehnder interferometer exists in the receiver.The transmission performance and security performance of stealth communication system have been demonstrated simulationly and experimentally.In addition,the influence of different bandwidth of ASE noise is studied.After 6 hours testing,the optical power of the signal is changed no more than 0.05d Bm,with the fixed Q factor of the eye diagram.Finally,3 Gb/s encrypted non-return-to-zero(NRZ)signal is successfully transmitted over25 km SSMF and 4.2 km dispersion compensation fiber(DCF).