Cheaper and more efficient photonic devices, such as lasers, optical fibers, and other light sources may be possible with confined light that is unaffected by imperfections in the material that confines it, according to new research. A team of physicists from Penn State, the University of Pittsburgh, and the University of Illinois have demonstrated in a proof-of-concept experiment that they can contain light in such a way that makes it highly insensitive to defects that might be present in a material. The results of the research appear online on June 4, 2018 in the journal Nature Photonics.