Stimulated Brillouin Scattering Beam Cleanup and Beam Phasing through Two Passive Channels

Stimulated Brillouin scattering (SBS) beam cleanup and SBS piston correction properties are explored. This research measures the beam cleaning and phase-conjugating properties of stimulated Brillouin scattering in an optical fiber. The first stage of this research began by coupling an aberrated beam into a long multimode 62.5 micron core fiber to demonstrate its beam cleanup properties. The Stokes beam obtained was shown to be the fundamental fiber mode, LP01. The second stage spatially dividedthe pump beam into two equal halves. Each half was then sent through two different channels. The path length of one channel remained fixed while the other path contained a retroreflector mounted on a piezoelectric movable stage to allow path length variation. The two channels were then tiled next to each other and the fringes were analyzed with a lateral shearing interferometer. Phasing from the two channels was not observed.