Fashion and photonics may seem an unlikely combination to inspire a product from the laboratories of Massachusetts Institute of Technology in Cambridge. However, blending the low-cost, high-volume processing techniques of polymer fibers found in textiles with the optical properties of dielectric mirrors has led to a development that may benefit both industries. Using thermal processing techniques, MIT researchers have constructed polymeric fibers with exterior, multilayered dielectric mirroring that provides a photonic bandgap in the mid-infrared. The spectral location of the photonic bandgap can be selected during fabrication. The fiber consists of a tough polymer core surrounded by 21 alternating layers of amorphous components As2Se3 and the high-temperature polymer PES.As described in the April 19 issue of Science, the fibers are more durable than typical planar dielectric mirrors, yet they retain directional photonic bandgaps and reflection efficiencies. The researchers predict that the fibers may someday be woven into textiles as a novel kind of optical bar code or as flexible radiation barriers. They also suggest that the fibers could serve as optical filters in telecommunications devices.