Effectively Single-Mode Chirally-Coupled Core Fiber

Download Whitepaper
Rapid advance in fiber laser technology has led to multi-kW average1 and multi-MW peak2, powers in diffraction-limited output beams. Technologically this advance is based on increasing fiber core size, which is typically 20-µm to 30-µm diameter for kW fiber lasers and >65-µm for multi-MW peak power generation. Such core sizes are well beyond single-mode limit in conventional index-guiding fibers, and achieving fundamental-mode output from a multimode core requires careful mode-management in these large-mode-area (LMA) fibers. This offsets many traditional technological advantages of conventional single-mode low-power fiber laser technology. It would be highly beneficial to replace LMA fibers with such index-guiding fibers, which could be managed just as telecom-type single-mode fibers (splicing, fiber pigtailing, fiber packaging, etc.), but which would allow large core sizes well beyond single-mode limit.