Page 210 - Chalcogenide Glasses for Infrared Optics

186 Cha pte r Ei g h t

122,000 psi, slightly higher than for C1 fiber, although the C1 measure-
ments used plastic-coated fiber. Another surprise was the strength of
both C1 and C2 fibers with 90-µm cores was independent of the strain
rates used in the measurements. A comparison of 500-µm core C2 fiber
results to the previous 500-µm C1 results indicated that C2 fiber was
stronger by 70 percent than C1 fiber. We realized we would not have
trouble making small-diameter ribbons with both C1 and C2 glass.
The first C2 bundle was made from 31 count ribbons made from
3
glass clad 100-µm core fibers on the 1-m drum. The bundle was about
2
7 mm when finished and contained 1054 fibers. The calculated active
area was 35 percent. Calculated transmission with Fresnel losses
would be only 24 percent. Figure 8.4 shows images of the bundle

FIGURE 8.4 Microscope photographs of the end of the fi rst C2 bundle.