A tunable optical add/drop multiplexer using a fiber-optic tapped delay-line transversal filter

Although optical fibers can provide an enormous bandwidth of several tens of THz in the low-loss transmission region, single channel transmission speeds are limited to less than a few tens of gigabits per second due to the speed limit of optoelectronic components used. Therefore, wavelength division multiplexing (WDM) technologies utilizing the fiber bandwidth more efficiently and economically are actively pursued for both optical links and optical networks applications. Optical add/drop multiplexer (OADM) has been considered as one of the key components used for selectively dropping/inserting wavelength channels from/into WDM networks. We propose a tunable OADM using a fiber-optic tapped delay-line transversal filter to provide the flexibility in the WDM network configuration.