CorActive High-Tech Inc.'s IRT-SU infrared transmission optical fibers are designed for the mid-IR from 2 to 5 µm. Nominal attenuation is <0.2 dBm, nominal numerical aperture is 0.20 and core refractive index is 2.4. The fibers' protective coating is composed of dual-coat acrylate, and their core/clad structure material is sulphide. Core and cladding diameters are 50 ±3% and 170 ±3%, respectively. The company says that the fibers produce ultralow loss and high nonlinearity and power capacity, and that they are bend- and polarization-insensitive.