Passive Sub-Carrier Multiplexing for Discriminating Overlapped Optical Spectra

A passive technique for multiplexing spectrally overlapping optical network signals is proposed and experimentally verified. The system utilizes arrayed fiber delay lines for multiplexing signal generation and offers simultaneous plotting of multiple optical spectra. Accurate recovery of individual spectrum of multiplexed long-period gratings spectra is experimentally demonstrated in a refractive index sensing application. This system provides an all-optical platform for economical multiplexing system in optical sensing networks.