Designing hollow-core multi-mode anti-resonant fibers for industrial high-power laser delivery

Abstract

We investigate the design of hollow-core fibers for the delivery of 10s of kilowatt average power from multi-mode laser sources where delivery through solid-core fibers is typically limited by nonlinear optical effects to 10s of metres of distance. A technique is presented for the design of multi-mode anti-resonant fibers that can efficiently capture and deliver light from these lasers. We analyze, by numerical simulation, the performance of two anti-resonant fibers designed using this technique to target lasers with M2 up to 13 and find they are capable of delivering MW-level power over multi-kilometres distances with low leakage loss, and at bend radii as small as 35cm. Pulsed lasers are also investigated and numerical simulations indicate that optimized fibers could in principle deliver nanosecond pulses with pulse energy greater than 100mJ over more than 1km. This would be orders of magnitude higher power and longer distances than in typical machining applications using state-of-the-art solid core fibers.