Hyperfine spectral phase coded optical CDMA: component technologies and networking applications

Summary form only given. This paper will focus on a specific coherent approach to OCDMA referred to as spectral phase coding. What is unique about this work over previous research is the fine spectral resolution at which our orthogonal phase codes are applied. Through the use of ultra-narrow spectral filtering techniques, including hyperfine DWDM filters and ring resonator technologies, our system is able to accurately tailor the spectral phase of each distinct frequency lines from a mode-locked laser operating at 5 or 10 GHz. This approach enables us to make the spectral width of the OCDMA signal, coded with an orthogonal phase mask covering 16 frequency bins, compatible with filtering and transmission components used in conventional DWDM systems aligned on a 100 or 200 GHz ITU grid. By combining coherent OCDMA with orthogonal coding and synchronous user operation, the largest overall system spectral efficiency can be achieved. In addition to describing the system architecture and device technologies, we will also present recent experimental results on practical optical networking applications, including the transmission of OCDMA with other conventional DWDM channels (inter-band compatibility). In addition, we show it is possible to have the OCDMA signal coexist with a conventional DWDM channel within the same passband (intraband compatibility). Finally, we demonstrate the ease at which OCDMA signals can be translated from one code to another code using completely passive optics, and discuss how this function can be exploited in a practical OCDMA networks.