The Flat-top 40ch Mux Demux is a high density, cost-effective and standalone passive optical module. It is based on a-thermal AWG technology with Flat-top shaped pass bands. By providing access up to forty 100GHz spaced channels in a 1U package, this unit maximizes the capacity of the C-band range. In conjunction with the transponders and amplifiers, the 40ch Mux Demux supports a wide range of architectures from simple point-to-point to amplified ring configurations.