Fast optical switch

An optical switching node comprising:

• a node controller;
• a first plurality of demultiplexers, each of said first plurality of demultiplexers adapted to receive an input link and demultiplex said input link into a plurality of input wavelength channels;
• a spectral-translation module adapted to receive said input wavelength channels and emit a plurality of internal optical signals;
• a plurality of star couplers, each of said plurality of star couplers including:
• a plurality of input ports, each of said input ports adapted to receive a given internal optical signal of said plurality of internal optical signals;
• and
• an output port emitting a star-coupler output signal that includes all of said internal optical signals received by said plurality of input ports;
• and
• a wavelength router having a plurality of inlet ports and a plurality of outlet ports, said wavelength router adapted to:
• receive at each inlet port one of said star-coupler output signals;
• and
• route internal optical signals from said star-coupler output signals to said plurality of outlet ports.

A node controller for an optical switching node, said optical switching node including a plurality of star couplers each star coupler having a plurality of input ports, said node controller comprising:

• at least one control input port adapted to receive a connection request;
• and
• a scheduler adapted to:
• determine, from said connection request, an output link;
• select a candidate star coupler from said plurality of star couplers;
• and
• attempt to find a free path through said candidate star coupler to an output wavelength channel in said output link.

A node controller for an optical switching node, said optical switching node including a plurality of star couplers, said node controller comprising:

• means for receiving a connection request;
• means for determining, from said connection request, an output link;
• means for selecting a candidate star coupler from said plurality of star couplers;
• and
• means for attempting to find a path through said candidate star coupler to an output wavelength channel in said output link.

A computer readable medium containing computer-executable instructions which, when performed by a processor in a node controller, cause the processor to:

• receive a connection request;
• determine, from said connection request, an output link;
• select a candidate star coupler from said plurality of star couplers;
• and
• attempt to find a free path through said candidate star coupler to an output wavelength channel in said output link.

In an optical switch including a plurality of input links and a plurality of output links, where said plurality of input links and said plurality of output links carry signals arranged in time frames having a predefined number of time slots, a method of operating said optical switch, said method comprising:

• assigning a first set of non-overlapping control time slots to each input link of said plurality of input links;
• assigning a second set of non-overlapping control time slots to each output link of said plurality of output links;
• time-locking an origin of said each input link to said optical switch, where said time-locking ensures time alignment of each said time frame received at said optical switch;
• interpreting signals received from said origin of said each input link during said first set of non-overlapping control time slots as input control signals;
• forming output control signals corresponding to said input control signals;
• and
• switching said output control signals to said each output link of said plurality of output links during said second set of non-overlapping control time slots.

In an optical switch including a switching fabric and a controller communicatively connected to said switching fabric, a method of operating said controller comprising:

• time-locking sources of a plurality of input channels to said switching fabric where said time locking ensures time alignment of time-slotted frames received at said switching fabric;
• receiving timing signals in said input control signal;
• forming output control signals corresponding to said timing signals;
• and
• transmitting said output control signals over an optical output control signal channel.