Chalcogenide glass fibers, transparent in the mid IR region, will soon find a wide range of applications, including military uses such as thermal imaging, sensing and tracking and remote spectroscopy. We have developed chalcogenide glasses, optical fibers and bundles, and hollow-core fibers suitable for some of these applications. Herein we describe the As2Se3 chalcogenide fibers and bundles with glassy core and TFE cladding, with a fiber diameter of 30-1000 μm. The optical loss, measured by CO2 laser and FTIR spectrometer in the temperature range of -197° C to 100° C is less than 1 dB/m in the 3-5 μm range and less than 10 dB/m at 10.6 μm. At longer wavelengths the attenuation is much higher. The fibers maintain their transparency in the temperature range of -40° C to 70° C (military standard range).Optical properties of hollow-core, chalcogenide glass cladding fibers were examined. Preceded by a theoretical background, experimental results concluding far-field patterns and bending effects are described. Hollow-core fibers are found to guide only a small number of modes.