Fig. 1. Schematic of chaos-based bidirectional signal transmission system

Fig. 2. Cross-correlation coefficient in the oupling-feedback coefficients plane

Fig. 3. Diagram of attractors of (a) SL1 and (b) SL2 in phase space

Fig. 4. Temporal traces of optical power of SL1 (blue),SL2 (red). Traces of SL2 have been shifted vertically to istinguish it from SL1. Insert shows the cross-correlation function between the two laser outputs

Fig. 5. Synchronization error of optics power

Fig. 6. (a) Transmission signal of two lasers; (b) absolute value of difference of two lasers Δm(t); (c) synchronization errors P1(t)-P2t shaped by Butterworth filter; (d) decoding by P1(t)-P2t (blue) and m1(t) (red) to send signal m2(t)

Fig. 7. Eye diagram of decoded signal