Abstract
Optical Add/Drop Multiplexers (OADM) are crucial components for the Wavelength Division Multiplexing (WDM) systems. These components allow wavelength selectively dropping and wavelength inserting of an optical data channel into a Dense WDM (DWDM) or into a Coarse WDM (CWDM) networks. Most of these components are based on Arrayed Waveguide Gratings (AWG), Fabry-Perot Filters, a combination of dielectric thin-film Mux. and Demux, Optical Fiber Couplers, Fiber Bragg Gratings (FBG) and Long Period Fiber Gratings (LPFBG). In this work, we provide an overview on the OADMs and its current technologies and give special attention to fiber components such as FBGs, LPFGs and tapered fibers.