Various embodiments of the present invention are directed to sensor networks and to methods for fabricating sensor networks. In one aspect, a sensor network includes a processing node (110, 310), and one or more sensor lines (102,202,302) optically coupled to the processing node. Each sensor line comprises a waveguide (116,216,316), and one or more sensor nodes (112,210). Each sensor node is optically coupled to the waveguide and configured to measure one or more physical conditions and, encode measurement results in one or more wavelengths of light carried by the waveguide to the processing node.