Thorlabs offers four variants of 0.22 NA step-index multimode optical fiber. Our standard glass-clad fiber has a silica core with fluorine-doped cladding and acrylate coating. For extreme temperature or ultra-high-vacuum environments, we also offer polyimide-coated fiber. Our solarization-resistant fiber does not degrade with UV. Finally, our TECS double-clad fiber has a TECS hard fluoropolymer coating over a doped silica cladding, for high-power use.