Surface-relief fiber Bragg gratings for sensing applications

We present a new type of fiber Bragg grating (FBG) in which we etch the grating into the flat surface of a D-shaped optical fiber. Instead of being written in the core of the fiber, as are standard FBGs, these surface-relief FBGs are placed in the cladding above the core. These gratings are a viable alternative to standard FBGs for sensing applications. We describe the fabrication process for etching Bragg gratings into the surface of D-fibers and demonstrate their performance as temperature sensors.     

HalfedgeCNN for Native and Flexible Deep Learning on Triangle Meshes

We describe HalfedgeCNN, a collection of modules to build neural networks that operate on triangle meshes. Taking inspiration from the (edge-based) MeshCNN, convolution, pooling, and unpooling layers are consistently defined on the basis of halfedges of the mesh, pairs of oppositely oriented virtual instances of each edge. This provides benefits over alternative definitions on the basis of vertices, edges, or faces. Additional interface layers enable support for feature data associated with such mesh entities in input and output as well. Due to being defined natively on mesh entities and their neighborhoods, lossy resampling or interpolation techniques (to enable the application of operators adopted from image domains) do not need to be employed. The operators have various degrees of freedom that can be exploited to adapt to application-specific needs.