Polymer-coated hollow fibers for medical infrared lasers: fabrication transmission and end sealing

摘要

Hollow fibers for medical IR lasers are fabricated by silver-mirror plating and liquid-phase polymer coating method. The coating thicknesses of the inner polymer layer of the fibers are designed so that the fibers show low-loss property for medical IR lasers with various wavelengths, such as Nd:YAG at 1.06 $mu@m, Er:YAG at 2.94 $mu@m and CO$- 2$/ at 10.6 $mu@m. Transmission characteristics of the fibers are shown. Small-bore fibers with inner diameters of 320 and 250 $mu@m for low-loss Er:YAG laser transmission are successfully fabricated. These fibers show better flexibility and small additional loss when bent. A new fabrication procedure without curing-process is also proposed. By considering that end sealing is always an important task for hollow fibers in medical applications, various sealing materials, such as polyimide, cyclic olefin polymer, and fluorocarbon polymer are introduced and transmission properties are summarized.