A multirate upgradable 1.6-Tb/s hierarchical OADM network

We report a hierarchical optical add-drop multiplexer (OADM) network that supports 10-, 40-, and 160-Gb/s data rates with the same bandwidth efficiency. The data rates can be upgraded without hardware modification in the OADM. This hierarchical OADM network is equipped with high capacity (1.6 Tb/s) for traffic growth, while providing different granularities for diverse bandwidth requirements as fine as 12.5 GHz in optical domain. We investigate the transmission penalty through the waveband OADMs, and compare the performance between all-through traffic and add-drop traffic of neighboring wavebands at 40-Gb/s rate.