Modular optical cross-connect architecture with optical wavelength switching

An optical cross-connect node for routing and switching wavelength communications channels at high speed, comprising:

• plural optical fiber input links and output links each containing a comb of plural wavelength channels;
• input wavelength converters, each connected to one of the input links being capable of converting a comb of plural wavelength channels to another comb of wavelength channels;
• an optical coupler having an input port for each input link and plural output ports;
• tunable optical filters, each connected to one of the optical coupler output ports for selecting a wavelength channel from the optical coupler;
• output optical wavelength converters, each connected to a corresponding tunable optical filter for converting the selected wavelength channel to a different wavelength channel;
• and
• optical combiners combining wavelength channels generated by some of the wavelength converters onto corresponding ones of the optical fiber output links.

A method of adding fiber optic links to an existing single stage optical cross-connect node that includes plural optical fiber input links and output links each containing plural wavelength channels, a single optical star coupler having an input port for each input link and plural output ports for combining all of the wavelength channels received from all of the input links and broadcasting the combined signal so that all of the input wavelength channels are available at each output port of the optical star coupler;

• tunable optical filters, each connected to one of the optical coupler output ports for selecting one of all of the input wavelength channels received on all of the input links;
• optical wavelength converters, each corresponding and connected to a tunable optical filter for translating the selected wavelength channel to a different wavelength channel;
• and optical combiners for combining selected wavelength channels generated by the wavelength converters onto corresponding optical fiber output links, comprising the steps of:
• determining a number of links to be added, and
• for each link to be added, coupling the link to an available input port of the optical star coupler, coupling an additional tunable filter and corresponding wavelength converter to an available output port of the optical star coupler, and connecting an output from the additional wavelength converter to an optical combiner.

A method of adding fiber optic links to an existing optical cross-connect node that includes plural optical fiber input links and output links each containing plural wavelength channels;

• input wavelength converters, each connected to one of the input links being capable of converting a comb of plural wavelength channels to another comb of wavelength channels;
• an optical coupler having an input port for each input link and plural output ports;
• tunable optical filters, each connected to one of the optical coupler output ports for selecting a wavelength channel from the optical coupler;
• output optical wavelength converters, each corresponding and connected to each tunable optical filter for translating the selected wavelength channel to a different wavelength channel;
• and optical combiners for combining selected wavelength channels generated by the wavelength converters onto corresponding optical fiber output links, comprising the steps of:
• determining a number of links to be added, and
• for each link to be added, coupling the link through an additional input wavelength converter to an available input port of the optical coupler, coupling an additional tunable filter and corresponding output wavelength converter to an available output port of the optical coupler, and connecting an output from the additional wavelength converter to an optical combiner.

In a transport network containing plural optical cross-connect nodes, each optical cross-connect node including:

• plural optical fiber input links and output links each containing plural wavelength channels, an optical coupler having an input port for each input link and plural output ports;
• tunable optical filters, each connected to one of the optical coupler output ports for selecting a wavelength channel;
• optical wavelength converters, each corresponding and connected to a tunable optical filter for translating the selected wavelength channel to a different wavelength channel;
• and optical combiners for combining selected wavelength channels generated by the wavelength converters onto corresponding optical fiber output links, a method comprising routing an input wavelength channel to plural output fibers and broadcasting the input wavelength channel from one optical cross-connect node over the transport network to other cross-connect nodes located in different geographical locations,
• wherein each optical cross-connect node further includes input wavelength converters each connected to one of the input links such that the input wavelength channel may be translated to other wavelength channels on the plural output fibers.