FABRICATION OF LONG LENGTHS OF LOW-LOSS IR TRANSMITTING AS40S(60-X)SE-X GLASS-FIBERS

Teflon clad and As40S60 glass clad As40S55Se5 fibers transmitting in t he 1-6 mu m wavelength region have been fabricated in lengths of about 50 m and with minimum losses of 0.098 and 0.65 dB/m, respectively. Sh ort lengths of the Teflon clad fiber possessed a minimum loss of 0.047 dB/m. While current fiber losses are dominated by extrinsic scatterin g and absorption, the calculated theoretical minimum loss is estimated to be 3.6 dB/km at 5.3 mu m and is limited by the contribution from t he weak absorption tail. Improvements in the purification and processi ng of the glasses into the optical fibers are required to reduce the l osses further.