Tunable filter based reconfigurable optical network

Summary form only given. Reconfigurable optical add/drop (ROADM) is one of the most important topics for today´s optical network, for the ROADM subsystem provides the node with the highest flexibility. Flexibility is defined as the ability to change the disposition of a wavelength from add, drop, or pass-through without interrupting traffic on any other wavelength. Two major approaches have been taken: wavelength selection switch (WSS) and tunable filter based optical add/drop (TOADM). In this talk, we report a few schemes, which provide certain degrees of reconfigurabilities. Typically, the flexibility and cost are contradictory to each other. We will compare these approaches in terms of performance, cost and availability.