Plastic bending of sapphire fibers for infrared sensing and power-delivery applications.

Sapphire fibers with diameters of 325-850 microm were plastically bent by CO(2) laser beams with typical bending radii as small as 2.8 mm. The additional optical loss caused by a single bend was less than 0.1 dB (at 900 nm), the damage threshold of the bent fibers was higher than 150 MW/cm(2) for Nd:YAG laser pulses, and the high mechanical strength of the bending area was also proved. Several successful applications of bent sapphire fibers have shown that plastically bent sapphire fibers are promising for use in IR sensing and power-delivery applications.