Fabrication of an antireflection microstructure on AgClBr polycrystalline fiber by single pulse femtosecond laser ablation

Polycrystalline infrared (PIR) fibers are used for numerous applications, one of those being power delivery CO2 ?lasers. However, the fiber tip surface’s transmittance cannot be increased with conventional antireflection coatings due to surface unevenness. Antireflection microstructures (ARMs) offer an alternative way increasing transmittance. In this work, ARMs were fabricated on AgClBr by single-pulse femtosecond laser ablation. A single-surface 92.8% at 10.6 µm, a ?laser operation wavelength, was achieved. The proposed method can help significantly improve systems’ efficiency, where ?lasers or sources operating in wide wavelength range is required.