Glasses in the Te-Br-Se and Te-I-Se systems show potential low losses in the 8–12 μm region. They are very stable against crystallization and against moisture. The lowest losses of a fiber at 10.6 μm, measured using a CO2 laser, is about 3 dB/m. The essential diffusion centers in these fibers have been proved to be bubbles. A power delivery experiment was made using a fiber having an attenuation of 5 dB/m. The power density of about 40 kw/cm2 can be injected into the fiber without damaging this fiber.