Fabrication of hollow optical fiber with a vitreous film for CO2 laser light delivery

Vitreous film based on the structural unit R2SiO, where R is an organic group, is newly used as the reflection layer in the hollow optical fiber for CO2 laser delivery. A smooth vitreous film is formed at room temperature by using the liquid-phase coating technique. The vitreous film-coated silver hollow optical fibers achieve low-loss property for lasers in the infrared regions by properly selecting fabrication conditions. A hollow fiber with thicker vitreous film designed for CO2 laser light showed acceptable loss as an output tip. It is shown that the hollow tip is of high durability to withstand several cycles of autoclave sterilization.