Page 213 - Chalcogenide Glasses for Infrared Optics

IR Imaging Bundles Made fr om Chalcogenide Glass Fibers 189

FIGURE 8.7 Air Force resolution target and “O” pattern image transmitted
through C4 bundle no. 26.

patterns. Figure 8.7 shows first the Air Force resolution target diagram
used in the evaluation and below an image demonstrating the perfor-
mance of the bundle in the “O” pattern. Notice individual ribbons are
clearly resolved. The top image in Fig. 8.8 shows the resulting image
when the “1” pattern is transmitted through the bundle. Not shown
is that most of the “3” pattern was also resolved, indicating a resolu-
tion limit of about 10 lp/mm for the bundle. The lower image in
Fig. 8.8 is of a human subject at a distance taken using the Agema 210
camera. A digital video recording was made of individuals in natural
light walking away from the bundle up to 50 ft and still discernible.
The objective lens on the end of the bundle was a 1-in-diameter