Teflon-clad As-S glass infrared fiber with low-absorption loss

Abstract
An As-S glass fiber with Teflon Fluorinated Ethylene Propylene (FEP) cladding has been fabricated. The transmission range of this fiber was 1–7 μm with two pronounced absorption peaks at 2.8 and 4.1 μm. It was found that these absorptions were caused by moisture adsorbed on the surface of the As-S glass as well as the hydrogen impurity due to the silica ampule. By removing these impurities the absorption loss was reduced and a minimum optical loss of 0.15 dB/m was obtained for this infrared fiber.