Electro-optically tunable multiple channels reconfigurable optical add/drop multiplexer
Being the fundamental device of wavelength division multiplexing (DWDM) system, reconfigurable optical add/drop multiplexer (ROADM) employed dozens of optical tunable filters classified by their tuning methods. Unfortunately, most of those techniques, due to their tuning principles, had low response speed and were unable to add or drop more than a single channel simultaneously. An electro-optically tunable ROADM was designed and analyzed. Fabricated on x-cut, y- propagation Ti:LiNbO3 waveguides, the electrodes converted the two polarizations of certain wavelengths with electro-optic effect, and hence realized the add/ drop function combined with two polarization beam splitters. Profiting from the separated structure of the interdigital electrodes, the sidelobe suppression, the bandwidth control and the multi-channel download were available as long as the voltages were applied properly.