Optical properties of single-crystal sapphire fibers

Publisher Website
Google Scholar
Abstract
Single-crystal sapphire fibers have been grown with the laser-heated pedestal-growth method with losses as low as 0.3 dB/m at 2.94 µm. With the incorporation of a computer-controlled feedback system, fibers have been grown with less than ±0.5% diameter variation, or ±1.5 µm for a 300-µm fiber. The losses in these fibers have been reduced further through a postgrowth anneal at 1000 °C in air, from 5.4 to 1.5 dB/m at 543 nm and from 0.4–0.3 dB/m at 2.94 µm. These fibers delivered 4.7 W at 10 Hz of Er:YAG laser power.