Abstract
The transmission characteristics of fused quartz fibers for flexible delivery of high power CW YAG laser light for material processings were examined. A novel optical system was developed and used to launch YAG laser light having a large beam divergent angles and high output power, into a small core diameter fiber. The comparison between graded index fibers and step index one's have shown that output laser beam intensity profiles are similar to the refractive index pro - files of the fiber used. Some welding experiments with these fiber systems showed that there is a remarkable welding penetration/welding bead width ratio enhancement if graded index fiber is used against step index one.
