Patent ID: 7184666

Claim:
A reconfigurable optical add-drop multiplexer, comprising: 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 said optical splitter, said 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; a plurality of pluggable optical filters optically coupled to said optical splitter, each of said pluggable optical filters filtering wavelengths so as to output a particular wavelength channel from the dropped optical signal; a 1:N optical splitter optically interposed between said optical splitter and said pluggable optical filters, said 1:N optical splitter splitting the dropped optical signal into N dropped optical signals at least some of which are respectively coupled to a corresponding one of said pluggable optical filters; an expansion port/splitter optically coupled to an output port of said 1:N optical splitter, said expansion port/splitter splitting one of the N dropped optical signals at least some of which are respectively coupled to a corresponding one of said pluggable optical filters; a second cassette having a plurality of slots capable of accepting a plurality of said pluggable optical filters; and an optical combiner optically coupled to said wavelength blocker and to an optical add path on which an optical add signal may be carried, said optical combiner combining the express optical signal having particular wavelengths expressed by said wavelength blocker and the optical add signal; wherein the reconfigurable optical add-drop multiplexer may be expanded or contracted by adding or subtracting said pluggable optical filters from the cassette; and wherein the reconfigurable optical add-drop multiplexer may be further expanded or contracted by adding or subtracting pluggable optical filters from the second cassette.