Research On True Random Number Generation Method Of SOA-FRL Multi-wavelength Chaotic Light Source

Chaotic optical signal is an important carrier of high-speed secure communication,with its high temporal unpredictability and wide enough noise-like power spectrum characteristics,and as an important source of physical entropy in the field of data encryption and key distribution in secure communication.Status,compared with traditional physical entropy sources such as thermal noise sources and corresponding true random number generators,has the unique advantage of high speed and easy control.In this paper,based on the semiconductor optical amplifier fiber ring laser,using the nonlinear effects of the semiconductor optical amplifier and the Kerr effect inside the fiber,a multi-wavelength chaotic light source system is constructed in the form of optical feedback.The characteristics of the parallel chaotic optical signal are improved by reference to the experimental system.The parameters of the random number are used as the standard to optimize the parameters of the signal postprocessing method,so as to realize the multi-channel parallel true random number output.The main research work of the thesis is as follows:(1)A method for generating a chaotic optical signal by a semiconductor optical amplifier fiber ring laser.Based on chaos theory,the conditions of laser chaos are derived.Based on optical transmission theory,the transmission equation of semiconductor optical amplifier fiber ring laser is established.The model is simulated by tool and the influence of different parameters on laser output is analyzed.The output signal of laser is analyzed.The chaotic characteristics of the broad spectrum are studied,and the multi-wavelength signals are analyzed independently.(2)Study the method of generating true random numbers based on chaotic optical signals.A high-speed photodetector and a high-speed oscilloscope are used to sample the photocurrent signal to obtain a time-domain sequence of the signal.The chaoticity of the signal is preliminarily verified by fast Fourier transform,autocorrelation function and Lyapunov exponent calculation.The amplitude of the signal is mapped according to the binary conversion precision,and the binary representation of the signal time domain sequence is obtained.Based on the XOR and LSB algorithms,the binary sequence is processed,and the algorithm parameters are optimized according to the experimental settings to improve the statistical randomness of the random numbers.For the delay information appearing at the laser loop period,the random sampling based subsampling method is used to suppress the hidden periodicity in the signal,and the output rate of the final random number is analyzed and improved based on the oversampling principle and method.(3)Experimental study on chaotic light source of semiconductor optical amplifier fiber ring laser,verifying its broadband chaos,tunable chaos,multi-wavelength chaotic output capability,and analyzing the experimental data.The chaotic signals in multiple experiments are post-processed and optimized,and a comprehensive random number evaluation is performed on the generated random number sequence using a professional random number test tool.For the wide-tuned chaotic optical signal,the optimal wavelength and bandwidth setting scheme is explored through experiments.For multiwavelength chaotic signals,the independence is calculated to evaluate its feasibility for chaotic optical communication.