These multimode step-index chalcogenide fibers have a chalcogenide core and chalcogenide cladding of lower refractive index. They will transmit light from 1-6 µm. They are flexible and do not suffer from serious degradation by moisture ingress as with certain other types of fiber designed for this wavelength. Chalcogenide has a glass type structure and fibers can be epoxied into connectors and polished using similar techniques to those employed for silica fibers. Although chalcogenide fibers do not have the tensile strength of silica fibers, they are quite easy to handle if given a suitable jacket for protection. These fibers are now offered with a choice of attenuation selection, the lowest loss fibers now offered have losses of 0.1 dB at 2.5 µm which is less than the best ‘dry’ silica fibers can achieve.