NEW ADVANCES ON OPTICAL-COMPONENTS NEEDED FOR FDM OPTICAL NETWORKS

Two critical components, needed for optical networks based on frequency division multiplexing and frequency reuse technologies, are presented. One is a fast tunable laser, yielding 24 discrete frequencies regularly spaced by 40 GHz around 1.53 mum. The laser can be switched randomly in less than 8 ns among these frequencies. Frequency routing of a 3 Gb/s bit stream in 10 ns-packets between 10 different destinations has been demonstrated with this laser. The second component is a broadband wavelength shifter capable of switching multigigabit data between optical frequencies in the 1.5-mum region. The device is tunable, cascadable, provides conversion gain and is nearly polarization insensitive. Data degradation after wavelength shifting is negligible. Such a device provides the means of reusing the limited set of frequencies given by the lasers and thus of realizing large size networks.