Photonic routing systems and methods computing loop-free topologies

A system for routing wavelengths in an optical network, the system comprising:

• a processor communicatively coupled to the optical network;
• and
• memory storing instructions that, when executed, cause the processor to
• responsive to a path request for a wavelength or group of wavelengths, determine a path through the optical network,
• determine a location on the path where wavelength blocking should occur to form a loop-free path in the optical network, and
• cause the wavelength blocking at the location.

A node in an optical network, comprising:

• a plurality of degrees connected to the optical network;
• optical devices configured to broadcast a plurality of wavelengths through the plurality of degrees;
• selectively enabled blocking elements at the plurality of degrees;
• and
• a processor configured to selectively enable a blocking element responsive to a loop-free path computed in a network in which node participates, based on a routing protocol which computes the loop-free path for at least one wavelength of the plurality of wavelengths.