Uniform polymer-film formation in hollow fiber by closed loop-coating method

摘要

A closed loop-coating method has been proposed in order to form a uniform polymer layer in the fabrication of cyclic olefin polymer-coated silver (COP/Ag) hollow optical fiber. A COP solution was flowed in a closed loop system, in which silver-coated tube was used as a part of it. Owing to the constant flowing speed of the solution and the airtight flowing environment, a uniform COP layer was formed, which is one of the most important parameters to improve the transmission properties of the hollow fiber. The method was successfully applied to the fabrication of hollow fibers with 2 meters length for near and mid- infrared lasers, such as Nd:YAG, Er:YAG and CO_2 lasers. Stable fabrication and better reproduction were also observed by using the new coating method.