Patent attributes
A fiber intensity reducer comprises a guided system fiber including a core and an outer cladding layer, an unguided fiber intensity reducing (FIR) section including a first fiber “end cap fiber” having a first end and a second end attached at its first end to the system fiber. A bond region is between the first end of the first fiber and the system fiber. The FIR section provides a softening point of at least 700° C. throughout and provides a sufficient transverse dimension along its entire length so that a beam of radiation received from the system fiber expanding therein avoids an interface with the air along its entire length. In one arrangement, the FIR section includes an outer capillary on the end cap fiber, wherein the capillary and the end cap fiber provide refractive index matching.