Abstract: The methods and apparatus of the present invention provide advantages for remote laser delivery systems that conduct high levels of light energy through a fiber optic cable to a selectable target surface. Helical fiber optic mode scramblers in accordance with the present invention are an integral portion of a fiber optic cable having a rigid curvature predetermined to advantageously influence the intermodal dispersion characteristics of the fiber optic cable. The various aspects of the present inventions may be employed to increase the useful life of a fiber optic cable, increase the energy throughput of a fiber optics cable, implement smaller sized scramblers, implement more efficient scramblers or to provide for robust implementations that are also easy to assemble. Scrambler assemblies in accordance with the present invention include a support structure and a cylindrical sleeve that work in tandem to maintain to the predetermined spiral curvature of the helical mode scrambler.