Performance evaluation of DBR active filters for very dense WDM systems

Summary form only given. The wavelength division multiplexing (WDM) technology will play an important role in next generation optical fiber communications. Optical demultiplexers and filters are key components in a WDM system to select the required optical channels. Crosstalk from adjacent channels occurs because of the imperfect nature of a demultiplexer. Active optical filters have the advantage of providing insertion gain instead of loss and are potentially good candidates for WDM demultiplexing. With its capability of tuning, locking, and gain control, the active filter is also possible to eliminate the problem of the band-narrowing effect caused by cascading mis-aligned passive optical 10 (de)multiplexer in all-optical networks. In the paper, the performance of DBR active filters used as demultiplexers in very dense WDM system is experimentally studied. Penalty-free transmission was achieved with channel spacing of 25 GHz at 2.5 Gb/s.