Delivery of Mid-infrared Femtosecond Laser by Chalcogenide Hollow-Core Fibers for Tissue Ablation

High-intensity mid-infrared femtosecond lasers in the 5- to 11-μm spectral range flexibly delivered through fibers exhibit exceptional potential for biomedical applications due to their alignment with fundamental molecular vibrational modes. However, the key issue is that no solid-core fiber is available that can deliver such intense mid-infrared femtosecond laser without suffering from high nonlinearity, low damage thresholds, and pulse distortion. To solve this problem, we successfully developed chalcogenide glass antiresonant hollow-core fibers that exhibit superior capabilities for delivering intense mid-infrared femtosecond pulses. The fiber achieves high transmission with loss as low as ~1 dB/m, excellent bending insensitivity, and near-diffraction-limited beam quality ( M 2 < 1.1). Notably, it supports the delivery of femtosecond pulses with peak powers exceeding 15 MW without introducing any observable pulse distortion or structural damage, surpassing conventional solid-core chalcogenide glass fibers by over an order of magnitude in damage threshold. Experimental validation demonstrates efficient murine corneal tissue dissection at a record-low power threshold of 60 mW (40% reduction compared to that of free-space systems), leveraging the characteristic amide I absorption band at 6.1 μm. This work pioneers the use of chalcogenide glass antiresonant hollow-core fibers for mid-infrared ultrafast laser applications, establishing a transformative platform for next-generation photonic medical technologies. Key advancements include broadband mid-infrared transmission with tailored spectral refinement, unprecedented power-handling capacity, and excellent spatial–temporal fidelity. The developed antiresonant hollow-core fiber paves the way for compact, flexible, and high-precision surgical tools, bridging the gap between laboratory innovation and clinical treatment.