A reconfigurable optical add-drop multiplexer is disclosed including an
optical splitter receiving an input optical signal and splitting the
input optical signal into a dropped optical signal and an express optical
signal; a wavelength blocker optically coupled to the optical splitter,
the wavelength blocker blocking particular wavelengths in the express
optical signal; a cassette having a plurality of slots capable of
accepting a plurality of pluggable optical filters; at least one
pluggable optical filter optically coupled to the optical splitter, the
pluggable optical filter filtering wavelengths so as to output a
particular wavelength channel from the dropped optical signal; and an
optical combiner optically coupled to the wavelength blocker and to an
optical add path on which an optical add signal may be carried, the
optical combiner combining the express optical signal having particular
wavelengths expressed by the wavelength blocker and the optical add
signal.