Low-crosstalk and compact optical add-drop multiplexer using a multiport circulator and fiber Bragg gratings

Three kinds of low-crosstalk and compact optical add-drop multiplexers (OADMs) based on a multiport optical circulator (MOC) with fiber Bragg gratings are proposed and demonstrated. For the MOC-based structure, there is a significant intraband crosstalk reduction of about 37 and 16 dB on the dropped and added channels, respectively, for the best proposed MOC-based structure as compared with the conventional structure. Bit-error rate performance and both intraband and interband crosstalk-induced power penalties of these MOC-based OADMs are examined in a 10-Gb/s system demonstration. Such a low-crosstalk, miniaturized, and compact OADR I may find important applications in dense wavelength-division multiplexing networks.