Simultaneous concealment of time delay signature in chaotic nanolaser with hybrid feedback

Simultaneous suppression of time delay (TD) signature in all observables of optical chaos emission, i.e. in both intensity and phase, has been achieved using two or more semiconductor laser (SL) sources or using two independent polarization components of single vertical cavity surface-emitting laser (VCSEL). In this paper, we examine for the first time the simultaneous TD feature suppression using a single nanolaser of single polarization state. The influence of hybrid optical/electrooptic feedback schemes employing either conventional, phase-conjugate, or grating mirror is evaluated. The concealment of TD signature is then investigated by means of the autocorrelation function. The results reveal the operational regions in each case with well eliminated TD signature in all observables. A secure communications system utilizing chaotic nanolaser is presented. Security analysis for a message transmitted in the form of a colored image is carried out which verifies the immunity of the system against possible statistical, brute force and differential attacks.