Specialty Optical Fibers Handbook

glass-transition temperatures as high as 680 8C, excellent durability, and a

relatively high refractive index of 1.84. In Fig. 13.4, loss data are given for a

typical germanate glass fiber. Although the losses are not as low as they are for

the fluoride glasses shown in Fig. 13.3, these fibers have an exceptionally high

damage threshold at 3 mm. Specifically, more than 20 W (2 J at 10 Hz) of Er/

YAG laser power has been launched into these fibers.

13.2.3 Chalcogenide Glass Fibers

Chalcogenide glasses are composed of two or more chalcogen elements nor-

mally selected from the small group including As, Ge, Sb, P, Te, Se, and S. When

these elemental materials ...