High Security Optical Metropolitan Area Network based on Advanced Modulation Techniques

We present an application scenario of a Passive Optical Metropolitan Area Network (PO-MAN). Multilevel Polarization Shift Keying (M-PolSK) is used to obtain 40 and 100 Gbps per single channel. Moreover, M-PolSKs allow to implement advanced protection techniques based on birefringence, an intrinsic electro-optical effect of optical fiber usually considered a constraint [1]. Nevertheless, we can exploit this effect to our advantage to protect the information. Unlike spread-spectrum technique in which information is protected by exploiting noise, this new paradigm exploits the birefringence effects specific of the optical fibers. These technological solutions are able to replace or coexist with the current ones and those under development, ensuring backward compatibility and flexibility of the networks.