Polarization-insensitive ultra-selective add and drop multiplexer using rectangular Brillouin-based filters

Ultra-selective separation-aggregation operation using polarization-insensitive rectangular optical filters based on stimulated Brillouin scattering in optical fibre has been realized. Extracting a ~2-GHz dual-polarization OFDM signal from an ultra-dense multiplex with ~300-MHz guard-band shows only ~1-dB penalty for QPSK format.