Bi-directional ROADM with one pair of NxN cyclic-AWGs for over N wavelength channels configuration

This paper presents a bidirectional optical add-drop multiplexer (BROADM) with permitting white spectral channels input in bidirectional configuration. The filter routing rule of array waveguide grating (AWG) is applied for the wavelength channels (WCs) that need to be added and dropped by using the corresponding tunable fiber Bragg gratings (FBGs). The other WCs pass through output by tuning FBG filter spectra away from the WCs. The bandwidth between two adjacent WCs of each pair of ports in AWG is wider than one channel spacing so that the filter spectra of FBG is tuned to free spectral range (FSR) region to realize the wavelength routing function without interfering other WCs. The WCs can be flexibly handled by installing the corresponding tunable FBG. Therefore, the proposed BROADM is more flexible and has higher transmission capacity in the optical network.