Utilizing polarization-multiplexing for free space optical communication transmission with security operation

Abstract

In this study, we present and demonstrate a 10 Gbit/s on-off keying (OOK) free space optical communication (FSO) system with signal security operation by using polarization-multiplexing method. A single wavelength can be separated two orthogonal polarization FSO signals, which mean the FSOp and FSOs respectively, by using two polarizers with mutually orthogonal polarization directions. And the FSOp and FSOs wavelengths can act as the data and interference channels for FSO connection. When the injected power of FSOs is > -30 dBm, the FSOp signal will be interfered seriously for security protection. In addition, the FSO signal can pass through 25 km fiber link and support 1000 m free space transmission length.