Patent ID: 8903242

Claim:
A directionless and colorless reconfigurable optical add/drop multiplexer (ROADM) for a plurality of clients, comprising: an add/drop interface for optical signals of at least one optical network, wherein each received optical signal is split by at least one optical splitter into optical signals which are applied to a downstream cross connector distributing the split optical signals to wavelength selectors of different clients, wherein each wavelength selector performs a wavelength selection of at least one wavelength from the distributed optical signals, wherein each wavelength selector comprises a wavelength selective switch, the wavelength selective switch comprising a grating filter and at least one of a liquid crystal on silicon switch (LCOS), a liquid crystal switch (LC), and a digital light processing switch (DLP), wherein an optical signal having a selected wavelength (λ) is applied to at least a plurality of client transponders of the plurality of clients, and wherein each client transponder is connected to a corresponding (1×M) optical switch switching an optical signal transmitted by said client transponder to an upstream cross connector distributing the transmitted optical signals to M optical combiners connected to said optical add/drop interface.