Theoretical And Experimental Research On The Concealment Of Time Delay Signature And Neuron-like Response Of Light-injected VCSEL System

With the development of the intelligent society,people have put forward higher requirements in the fields of information security,signal storage and calculation.But limited by electronic bottlenecks such as bandwidth and power consumption,it is difficult for traditional electrical devices to further improve the processing and transmission speed of information.Therefore,semiconductor laser-based signal generation and processing methods with high bandwidth and high speed have gradually become a hot spot of research.Vertical cavity surface emitting laser(VCSEL)has received extensive attention in recent years due to its advantages of low threshold current,low power consumption,high coupling efficiency with optical fibers and easy two-dimensional integration.By introducing different external disturbances,the output of VCSEL will show rich dynamic characteristics such as cycle,chaos and neuron-like excitability response.It has also been widely used in the fields of communication,cryptography,and brain-like neuroscience.Therefore,studying the response of VCSEL under different light injection conditions is of great significance to promote the development and application of VCSEL in the information field.This thesis mainly studies the characteristics of VCSEL output under chaotic injection and rectangular wave injection.The main innovations are as follows:1.A mutually coupled network based on three VCSELs is designed,and existing experimental instruments are used to discuss the influence of injection intensity and frequency detuning on the time delay signature(TDS)of the chaotic output.Using the autocorrelation function as a quantitative analysis method,three low-latency chaotic outputs are obtained in three VCSELs at the same time.Compared with the mutually coupled system,the designed network greatly expands the parameter space that can realize the concealment of TDS.2.Two chaotic systems combining two different lasers,DFB and VCSEL,are designed.First,through experimental methods,the DFB chaotic output with time delay signature generated by self-feedback is injected into the VCSEL,and the influence of the injection strength,frequency detuning and injection polarization state on the concealment of TDS is studied.Then,two DFB chaotic outputs with TDS are injected into the two different polarization modes of the VCSEL.Through the beam splitting function of PBS,two chaotic outputs are obtained,and the influence of frequency detuning and injection intensity on the concealment of TDS are also studied in detail.3.A neuron-like response system based on VCSEL is designed,and the neuron-like inhibitory response function under double pulse injection was realized in the experiment.The combination of DFB and intensity modulator is used to generate the required input signal,which is then injected into the VCSEL working below the threshold.Based on the principle that there is a dynamic balance between the generation and disappearance of carriers in the VCSEL,within a certain injection pulse width and time range,a simple neuron-like inhibitory response function is realized..