Abstract: A system may perform an uptapering process to cause a signal fiber to have a fiber core with a first uptapered thickness profile and a fiber cladding with a second uptapered thickness profile. The system may perform, after performing the uptapering process, an uptapering removal process to cause the fiber cladding of the signal fiber to not have the second uptapered thickness profile. The system may perform, after performing the uptapering removal process, a bundling process to bundle the signal fiber and a set of one or more pump fibers in a bundle configuration. The system may perform, after performing the bundling process, a bundle unification process to cause the bundle configuration to form a unified bundle configuration. The system may perform, after performing the bundle unification process, an attachment process to cause an end of the unified bundle configuration to attach to an end of an output fiber.

Abstract: A modal instability of a fiber amplifier may be reduced by coupling, e.g. splicing, a length of passive multimode optical fiber to an active multimode optical fiber of the fiber amplifier. Upon launching light into the passive optical fiber, some higher order transversal modes may be excited in the passive optical fiber. The higher-order modes may interfere with the fundamental mode in the passive multimode optical fiber. However, the intermodal interference of the launched modes does not cause thermal gradients in the passive optical fiber. Upon propagation in the passive multimode optical fiber, the excited optical modes may lose mutual coherence, causing a reduction of contrast of the intermodal interference pattern along the doped core of the active optical fiber, effectively reducing modal instability in the active optical fiber.

Abstract: A modal instability of a fiber amplifier may be reduced by coupling, e.g. splicing, a length of passive multimode optical fiber to an active multimode optical fiber of the fiber amplifier. Upon launching light into the passive optical fiber, some higher order transversal modes may be excited in the passive optical fiber. The higher-order modes may interfere with the fundamental mode in the passive multimode optical fiber. However, the intermodal interference of the launched modes does not cause thermal gradients in the passive optical fiber. Upon propagation in the passive multimode optical fiber, the excited optical modes may lose mutual coherence, causing a reduction of contrast of the intermodal interference pattern along the doped core of the active optical fiber, effectively reducing modal instability in the active optical fiber.