Fig. 1. Structure of the monolithically integrated parallel chaotic sources. (a) Micrograph picture of the AFL array; (b) schematic diagram of the single device structure. TAR, tail absorption region; EI, electrical isolation; DFB, distributed feedback; SOA, semiconductor optical amplifier.

Fig. 2. Experimental setup for the testing of DFB-SOA chaotic laser. ISO, optical isolator; PD, photodetector; DC, direct current; OSA, optical spectrum analyzer; OSC, oscilloscope; ESA, electronic spectrum analyzer.

Fig. 3. Mapping diagram about the spectral dynamics of the integrated AFL with the increase of I_DFB when the I_SOA is fixed at 70 mA.

Fig. 4. Experimental results of classification displayed, about different spectral dynamics with the increase of I_DFB, respectively. (a) DMC state; (b) SMC state; (c) P-1 oscillation state; (d) SM state.

Fig. 5. Experimentally obtained SM chaotic spectrum of the chaotic laser array. The black curve represents the single-mode laser as a reference.

Fig. 6. Experimentally obtained power spectra of the chaotic laser array from channel 1 to channel 8. The black curve represents the noise floor, the orange curve represents the single-mode laser, and the blue curve represents the chaotic laser.

Fig. 7. (a) Statistical results of chaotic bandwidths for the chaotic laser array. (b) Time-domain sequence of the first chaotic channel.

Fig. 8. Illustration of the generation for parallel random bit streams for chaotic laser array.

Fig. 9. Histogram distributions for (a) raw signal intensity and (b) differential intensity after postprocessing of delay-subtracting; (c) probability distribution with 3-LSBs extraction; (d) corresponding ACF curve of the bit stream.

Fig. 10. Results of NIST tests for all eight chaotic channels about two indices: p-value and proportion.

Fig. 11. CCFs of any two sequences from these eight parallel temporal subsequences. Four examples are selected to display.