Fiber used in a high performance laser comprises a fiber core, a molded hexagon or other polygon casing surrounding the core, and a coating surrounding the casing

摘要

Fiber comprises a fiber core; a casing surrounding the core; and a coating surrounding the casing. The casing has a cross-sectional shape in the form of a molded hexagon or a polygon with (2n-1) sides (where n is more than 2). A fiber comprises a fiber core, a casing surrounding the core, and a coating surrounding the casing. The casing has a cross-sectional shape in the form of a molded hexagon or a polygon with (2n-1) sides (where n is more than 2). Preferred Features: The core is elliptical and has a double refraction of 1 x 10<-6> to 1 x 10<-4>. The outer diameter of the fiber is at least 125 mu m. The coating is made from a polymer. The fiber core is doped with Yb, Nd, Er, Er/Yb or Tm.