Page 198 - Chalcogenide Glasses for Infrared Optics

174 Cha pte r Se v e n

Monitor cure: DEFT self-priming topcoat
On application

Absorbance

Fully cured
3500 3000 2500 2000 1500
–1
Wavenumber (cm )
FIGURE 7.16 Cure of a urethane paint as measured by the Semsiv IR
refl ectance probe. The example shows how the probe can be used to monitor
the cure of a coating after its application. This is a urethane paint system,
and the curing reaction is followed by the decrease in absorbance of the
isocyanate functionality.

substantial energy from the CW CO laser. The main application of
AMI IR glass fibers has been chemical analysis and chemical reaction
studies. Measurements of this kind were not possible before the
development of both the FTIR spectrophotometers and chalcogenide
glass fibers covering the wavelength ranges used in analysis. For
AMI, IR fibers have been a small but continuous business since the
beginning in 1990. Never has this activity been a large portion of total
sales, but AMI considers this activity important.

7.4 Extrusion of Chalcogenide Glasses
AMI became involved in the extrusion of chalcogenide glasses in an
unusual manner. In late spring of 1993, we had a visit from Jacob
Fraden, founder of the company Thermoscan. He had developed an
electronic device to measure a person’s temperature from the infra-
red emission of the tympanic membrane of the ear. Figure 7.17 shows
the device as advertised by Dillards in the Dallas Morning News in
1992. The main market thrust was for use with infants and small chil-
dren. Sales were already in the thousands. The purpose of Jacob
Fraden’s visit was to see if we could produce small, inexpensive
infrared glass light pipes to replace the light pipe in current use.
When a company has a device being sold on the market in quantities
of thousands a month, reduction in cost by $1 or $2 of a single
element used in its construction leads to a substantial increase in
profit. The current light pipe was a short piece of copper tubing that