Experimental Evidence of Time-Delay Concealment in a DFB Laser With Dual-Chaotic Optical Injections

The experimental evidence and characterization of time-delay concealment in a semiconductor laser (SL) with dual-chaotic optical injections (DCOIs) are reported. Autocorrelation function and permutation entropy are employed to extract the time-delay signature (TDS). Our experimental results show that both TDSs associated with the dynamics of master lasers or only one of the two TDSs can be concealed in the SL with DCOI, depending on the choices of the injection ratio and frequency detuning of the two injection lights. The experiments are in good agreement with the simulations. Furthermore, the possibility to use the chaotic signal with no obvious TDS generated by the SL with DCOI for high-speed random number generation is experimentally demonstrated.