Page 177 - Chalcogenide Glasses for Infrared Optics
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CHAPTER 7
Glass Processes for
Other Applications
7.1 AMI as Supplier of Chalcogenide Glasses
for IR Fibers
The first involvement of AMI in the development of infrared fibers
based on chalcogenide glasses was that of a materials supplier. There
was a 2-year research agreement made between Texas Instruments
and Galileo Electro-Optics in 1982 to jointly develop fibers and fiber
devices based on the use of TI 1173 glass. The glass was to be pro-
vided by TI and the silicate fiber-based technology of Galileo Electro-
Optics applied to the infrared glass. The program was negotiated
with the help of AMI colleague Thomas Loretz who at that time was
director of materials research and engineering at Galileo Electro-
Optics. The program made good progress based on TI 1173 glass and
was the first in the industry, 1985, to announce the availability of chal-
cogenide glass fibers. The TI results from the program were reported 1
in Optical Engineering in 1987. The final optical-mechanical properties
2
from Galileo Electro-Optics were also reported in 1987. However,
after the 2-year program ended, TI would no longer supply the TI
1173 glass. AMI began to supply glasses in 1985 and 1986 to Galileo
Electro-Optics and others in the form of billets and rods of core glass.
Results relayed to AMI were not good relative to attenuation at the
wavelength of 10.6 µm, critical for use with the CO laser. From the
2
AMI standpoint, our evaluation results for the glasses supplied indi-
cated that much better performance should have been experienced.
The reaction at AMI was that the silicate fiber-based techniques they
used were not suited for the chalcogenide glasses. As an example, we
later learned that silicate fibers were often pulled at speeds up to
70 mph. In the marketplace, another factor was the brittleness of
TI 1173 and its tendency to crystallize. Glass compositions other than
TI 1173 were selected and turned into fibers at Galileo, but the greatest
difficulty in using the fibers was breakage.
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