An explanation of SRS beam cleanup in graded-index fibers and the absence of SRS beam cleanup in step-index fibers.
Beam cleanup via stimulated Raman scattering in multimode fibers is modeled by numerically considering the competition between the Stokes modes of graded-index and step-index fibers. The relative gain of each Stokes mode is calculated by considering the overlap the various pump and Stokes modes of the fibers. Mode competition in a graded-index fiber favors the LP(01) Stokes mode while mode competition in a step-index fiber does not favor the LP(01) Stokes mode. This model explains why beam cleanup has only been reported for graded-index fibers and not for step-index fibers.
Terry
Nathan B
NB
Air Force Institute of Technology, 2950 Hobson Way, Wright-Patterson Air Force Base, OH 454332, USA. nathan.terry@wpafb.af.mil
Alley
Thomas G
TG
Russell
Timothy H
TH
D003198:Computer Simulation; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008027:Light; D008962:Models, Theoretical; D055100:Optical Fibers; D015203:Reproducibility of Results; D012542:Scattering, Radiation; D012680:Sensitivity and Specificity