Research On Multi-Objective Optimization Of Chaotic Laser Output From Semiconductor Laser System

Compared with general laser,chaotic laser has the advantages of noise-like random spectrum and strong anti-interference and is widely used in chaotic secure communication and chaotic lidar.Semiconductor lasers have become the first choice to output chaotic laser because of their small size,low price and easy integration.However,semiconductor lasers need to add external disturbances to output nonlinear chaotic laser,which makes the output chaotic laser have obvious delay characteristics and narrow signal bandwidth,which seriously affect the application of chaotic laser.It is necessary to optimize the chaotic laser output from the semiconductor laser system.The chaotic laser is very sensitive to the parameter range of the semiconductor laser system.Some small changes will have a great impact on the chaotic laser performance.It is proved that it is feasible to optimize the chaotic laser signal by optimizing the laser system setting.The dynamic equation of semiconductor laser system is an important means of chaotic laser simulation.It is necessary to select appropriate calculation methods to ensure highquality calculation accuracy.Therefore,the widely used real imaginary part decomposition calculation method in China and the less widely used amplitude phase decomposition calculation method in China are compared through the maximum Lyapunov exponent and phase diagram.It is found that there is no obvious difference between the two calculation methods at low complexity,but at high complexity,The accuracy of the real part imaginary part decomposition method is higher than that of the amplitude phase decomposition method,and this phenomenon is compared and analyzed.Secondly,the system structure of semiconductor laser with optical injection optical feedback is optimized through investigation.Because of its wide research and complex system,it is used as a multiobjective optimization laser system.Based on this model,the population size and cross distribution index of the multi-objective optimization algorithm are set,and the semiconductor laser system parameters such as feedback intensity,linewidth enhancement factor and injection intensity are selected as the optimization parameters.The appropriate parameter range is selected by the multi-objective optimization algorithm.Through the1000 generation multi-objective optimization,it is found that there is a mutual restriction relationship between the bandwidth broadening of chaotic laser and the suppression of delay characteristics.The better parameter configuration of semiconductor laser system is obtained by local optimization through directional multi-objective genetic algorithm,The output laser performance of the semiconductor laser system optimized by simulation inversion is consistent with the results obtained by the multi-objective optimization algorithm.