Cascaded all-optical sub-channel add/drop multiplexing from a 1-Tb/s MB-OFDM or N-WDM super-channel with ultra-low guard-bands

We show cascaded 100-Gb/s sub-channel add/drop from a 1-Tb/s MB-OFDM or Nyquist-WDM super-channel having ultra-low inter-sub-channel guard-bands within a recirculating loop via a hierarchical ROADM using high-resolution filters, showcasing up to 1000-km transmission reach and five ROADM node passages for the add/drop sub-channel when hybrid Raman-EDFA is used.