In this paper, high quality chalcogenide infrared-transmitting As40Se60 and As38.8Se61.2 glasses were prepared and characterized for single mode glass fibers. In order to obtain high purity glasses, the starting materials, As and Se (99.9999%), were purified using a distillation method, which required heat treatment under vacuum using silica tubes and a liquid N-2 trap system. As40Se60 and As38.8Se61.2 glasses are chosen as core and cladding, respectively. From the differential scanning calorimetry (DSC) results, the glass transition temperature (T-g) of the As40Se60 and As38.8Se61.2 glasses was 183 degrees C and 173 degrees C, respectively. Infrared transmission of the two glasses shows good transmittance over the range of 1-12 mu m. There is a slight absorption in both glasses at similar to 4.4 mu m which is related to Se-H bonds. In order to measure the refractive index over the range of similar to 2 -12 mu m, prisms of 40 mm x 40 mm x 15 mm with 20 degrees angles were made and were carefully polished. It was found that the refractive indices of As40Se60 were slightly higher than those of the As38.8Se61.2. (C) 2014 Elsevier Inc. All rights reserved.