Mid-infrared all-solid anti-resonant chalcogenide fiber with large mode area and coupling tolerance

Large-mode-area anti-resonant fibers (LMA ARF) with high beam quality have the potential to revolutionize mid-infrared high-power laser delivery by mitigating mode instabilities and nonlinear degradation. However, their tens-of-microns mode field diameters and small numerical aperture significantly increase the mode field mismatch and coupling complexity, respectively. In this work, an LMA all-solid anti-resonant fiber-microlens with a robust operation of high beam quality in the mid-infrared region was designed and prepared. It can significantly stabilize the efficiencies of coupling and transmission at a large radial offset. Consequently, this AS-ARF demonstrates substantial potential for advancing mid-infrared laser power delivery via fiber, ensuring exceptional beam quality throughout the process.