Interferometric cross talk-free optical add/drop multiplexer using cascaded Mach-Zehnder fiber gratings

An optical add/drop multiplexer (ADM) has allowed us to exploit scalability in wavelength-division multiplexing (WDM) networks. A Mach Zehnder interferometer with photoinduced fiber Bragg gratings (MZ FG) is a promising device as a wavelength-selectable optical ADM circuit. In this study, we will present a novel method to provide the interferometric cross talk-free device based on a cascaded MZ-FG.