Fiber Bragg Grating-Based Three-Dimensional Multipoint Ring-Mesh Sensing System With Robust Self-Healing Function

By utilizing the cyclic filtering and free spectral range characteristics of an arrayed waveguide grating (AWG), we propose and experimentally demonstrate a novel 3-D ring-mesh sensing system with comprehensive self-healing function. The Bragg wavelengths of the employed fiber Bragg grating-based optical sensors are periodically assigned, with respect to the AWG. The proposed ring-mesh topology is constructed by
$2 \times 2$
optical switches to link the ring-based subnets in a meshed architecture. Moreover, a simple and cost-effective signal sensing processor, provided by the AWG, is employed for classifying the sensing signals and monitoring the sensing elements. With the same constructional building block, the proposed sensing system can be easily scaled up which provides more self-healing paths in a self-reproduced manner. In addition, we also bring up a routing algorithm to seek for an optimal sensing path that has the least accumulated power loss to deal with any possible sensing point outage when the sensing system is scaling up.