Optical fiber assembly for mitigating stimulated brillouin scattering

An optical fiber assembly for mitigating stimulated Brillouin scattering (SBS), the optical fiber assembly comprising:

• an optical fiber comprising:
• a core extending along a longitudinal fiber axis;
• and
• one or more claddings surrounding the core and extending along the longitudinal fiber axis, an innermost one of the one or more claddings having a refractive index that is lower than a refractive index of the core, the one or more claddings comprising an inner doped region contiguous to the core, the inner doped region having a composition comprising a cladding glass material doped with at least one acoustic-velocity-lowering and refractive-index-raising dopant and at least one acoustic-velocity-lowering and refractive-index-lowering dopant, the composition of the inner doped region being selected to provide the optical fiber with a radial acoustic velocity profile in which a longitudinal acoustic velocity within the inner doped region is equal to or less by at most 0.5% than a longitudinal acoustic velocity within the core;
• and
• a winding support configured to hold the optical fiber in a winding arrangement,
• wherein the radial acoustic velocity profile and the winding arrangement of the optical fiber provide SBS mitigation by reducing a mode overlap between an optical mode guided in the core and acoustic modes comprising a guided acoustic mode and a leaky acoustic mode.