Investigation On The Autocorrelation Performance And Bandwidth Of Chaotic Semiconductor Lasers

The investigation of higher bandwidth and lower autocorrelation chaotic lasers has became a hot topic because of the wide applications of chaotic lasers,such as chaotic secure communication and the physical entropy source of high speed true random numbers.In this paper,we present two schemes to eliminate the autocorrelation and broaden the bandwidth of chaotic laser from distributed feedback semiconductor lasers(DFB-SL).These two schemes are DFB-SL with double phase modulated optical feedback based on external optical injection(DFB-SL-DPMOF-EOI)and DFB-SL with double filtered optical feedback based on external optical injection(DFB-SL-DFOF-EOI)respectively.The numerical results show that time-delay signature(TDS)of chaotic laser from these two schemes is effectively eliminated in the range of selected parameter values.Namely,the autocorrelation of chaotic laser is decreased.Under the parameter conditions of effectively suppressing TDS,the bandwidth of the chaotic laser light from the systems corresponding of these two schemes is investigated.The results show that the bandwidth increases with increasing external optical injection coefficient and the master lasers' s pumping factor,respectively;With raising the frequency detuning between master and slave lasers,the bandwidth increases firstly.After reaching the maximum value,the bandwidth decreases gradually.Both the maximum values of the bandwidth of chaotic laser from these two schemes are about 18.4GHz.Then the chaotic laser which is obtained in this thesis and has high bandwidth and low autocorrelation are used as the physical entropy source.The generation of physical random numbers is numerically investigated.And the random numbers pass the test of performance index.