Several chalcogenide glass fibers with Teflon cladding and glass cladding were prepared for infrared optical application. A minimum transmission loss, at C02 laser wavelength, of 0.9 dB/m was attained in SeTel glass fiber. The CO and CO2 laser power transmission characteristics of fibers were investigated. Selenide and telluride glass fibers yielded damage thresholds lower than sulfide glass fiber because of their large temperature dependence of refractive index and transmission loss. Deliveries of 80 W of CO laser light in AsS glass fiber, and 10 W of CO2 laser light in GeSeTe glass fiber, were attained. An AsS fiber bundle of 8400 cores was prepared, which could deliver a clear thermal image below 100 °C. Prepared fibers were also found useful for low temperature monitoring and gas sensing in narrow or restricted spaces.