Abstract

Being capable of light localization in the large air-filled core, microstructured hollow-core fibers (HCF) are highly promising for a long-distance high-power ultra-short pulse (USP) delivery due to extremely low fiber nonlinearity. Among them negative-curvature revolver hollow-core fiber (RHCF) having a cladding formed with a single layer of non-touched cylindrical silica glass capillaries [1] is the most beneficial for high power USP delivery owing to its cost-effective fabrication technology (due to much more simple fiber design) in comparison with hypocycloid Kagome [2] or hexagonal-cladding [3] hollow-core photonic crystal fibers; very low group velocity dispersion (GVD) [4] and outstanding localization of the fundamental mode (more than 99.993%) [1], which means only ~10⁻⁴ part of total optical power travelling inside silica glass elements of the fiber. In this work we develop and optimize high-power all-fiber USP MOPA source emitting femtosecond pulses with ~1 MW peak power in the telecom spectral band near 1.56 µm and demonstrate long-distance high power pulse delivery through 11.7 m-long air-filled RHCF with attenuation of less than 30 dB/km and acceptable output beam quality (M²≈1.4).

© 2017 IEEE