Described herein are photonic communication platforms that permit use by multiple users in a secure way. A platform comprises a substrate, a first photonic circuit monolithically integrated with the substrate, and a second photonic circuit monolithically integrated with the substrate. The first photonic circuit is patterned with a first plurality of photonic modules, the photonic modules of the first plurality being copies of a common template photonic module The second photonic circuit is patterned with a second plurality of photonic modules, the photonic modules of the second plurality being copies of the common template photonic module. A photonic link couples the first photonic circuit to the second photonic circuit. A controller optically isolates the first photonic circuit from the second photonic circuit by optically interrupting the photonic link.