Fluoride glasses are being considered for use in long distance mid-IR transmitting optical fibers. The multiphonon edge of these fibers is shifted to longer wavelengths compared with silica fibers. The intrinsic loss is, therefore, lower (≤0.01 dB/km) and occurs at −2.5 μm. Uses for these fibers include ultralow-loss communication links, radiation resistant links, remoting of IR focal plane arrays, IR power delivery, low-temperature sensors, and medical and remote spectroscopic analysis. In addition, this ultralow-loss optical fiber may be used for fiber guided missiles with ranges of >500 km. Most of the interest, however, has been focused on development of very long (thousands of kilometers) repeaterless communication links. Such repeaterless links may decrease system cost and cable weight while increasing overall reliability and ease of repair compared to silicate optical fibers.