Experimental demonstration of an 8-Gbit/s free-space secure optical communication link using all-optical chaos modulation

For the first time, to the best of our knowledge, we experi-mentally demonstrate a high-speed free-space secure optical communication system based on all-optical chaos modu-lation. The effect of atmospheric turbulence on optical chaos synchronization is experimentally investigated via a hot air convection atmospheric turbulence simulator. It is shown that, even under moderately strong turbulent condi-tions, high-quality chaos synchronization could be obtained by increasing the transmission power. Moreover, a secure encryption transmission experiment using a high bias cur-rent induced chaotic carrier for 8-Gbit/s on-off-keying data over a similar to 10-m free-space optical link is successfully demon-strated, with a bit-error rate below the FEC threshold of 3.8 x 10-3. This work favorably shows the feasibility of opti-cal chaotic encryption for the free-space optical transmission system.(c) 2023 Optica Publishing Group