Random bit generation is experimentally demonstrated using a semiconductor laser driven into chaos by optical injection. The laser is not subject to any feedback so that the chaotic waveform possesses very little autocorrelation. Random bit generation is achieved at a sampling rate of 10 GHz even when only a fractional bandwidth of 1.5 GHz within a much broader chaotic bandwidth is digitized. By retaining only 3 least significant bits per sample, an output bit rate of 30 Gbps is attained. The approach requires no complicated postprocessing and has no stringent requirement on the electronics bandwidth.

The multistability in a single-mode distributed feedback semiconductor laser with delayed optoelectronic feedback is observed experimentally. For a given delay time, the observed dynamical state of the laser output is critically dependent on the process of varying the delay time and is limited by the range of variation. Various routes of delay time variation results in multistabilities characterized by states of different time series and power spectra.

No abstract

No abstract

No abstract