Extruded Antiresonant Hollow Core Fibers for Mid-IR Laser Delivery

We report an overview of our recent progress in the design and fabrication of soft-glass based antiresonant hollow core fibers (AR-HCFs) for laser delivery in the mid-IR (<tex>$5-11\ \mu\mathrm{m}$</tex>). The fibers are fabricated by extrusion and subsequent drawing, using two different glasses: tellurite (70TeO<inf>2</inf>-13ZnO-10BaO-7Na<inf>2</inf>O), and chalcogenide (IG3, Ge<inf>30</inf>As<inf>13</inf>Se<inf>32</inf>Te<inf>25</inf>). The fabricated tellurite AR-HCFs can operate from 5 to <tex>$7\ \mu \mathrm{m}$</tex> wavelength, and the IG3 AR-HCFs can operate further up to <tex>$11\ \mu\mathrm{m}$</tex> wavelength. The numerical and experimental losses of the fundamental mode for the fabricated fibers are on the few dB/m level. Numerical modeling study indicates that, by improving the uniformity and shape of the capillaries, losses down to 0.1 dB/m in the mid-IR (5 to <tex>$11\ \mu\mathrm{m}$</tex>) should be possible, making this solution attractive for the mid-IR laser delivery, such CO, CO<inf>2</inf> and quantum-cascade lasers.