Specialty Optical Fibers Handbook

21.2 OPTICAL AND MECHANICAL

CHARACTERISTICS OF SINGLE-CRYSTAL

SAPPHIRE FIBER

The appeal of using sapphire fiber as an optical waveguide is driven by its

capability to transmit light radiation at longer wavelengths into the IR than glass-

based fibers (up to 3.5 mm) coupled with some of its superior physical and

mechanical properties (melting point in excess of 2000 8C, chemical inertness,

high laser-power thresholds, etc.). Sapphire fibers are crystalline in nature and not

amorphous glasses. There are two types of crystalline fibers: single-crystal (SC)

and polycrystalline (PC). Meter-long lengths of SC fibers have been made only

from a handful of materials out of a possible pool of more than 80 IR transmissive

crystalline materials. In this context, ...