Large Mode Area Solid-Core Photonic Bandgap Yb-Doped Fiber With Hetero-Structured Cladding for Compact High-Power Laser Systems
Olivier Vanvincq, Andy Cassez, Rémi Habert, Hicham El Hamzaoui, Karen Baudelle, Stéphane Plus, Damien Labat, Mohamed Bouazaoui, Yves Quiquempois, Géraud Bouwmans, Frédéric Audo, Thierry Chartier, É. Lallier, Laurent Bigot
Abstract
We report on the design, realization and testing in pulsed amplification regime of a double-cladding, large mode area, polarization maintaining, solid core photonic bandgap fiber with Yb-doped core obtained from a Sol-Gel -made material. A specific hetero-structuration of the cladding has been applied to efficiently reject the higher-order modes, making the fiber single-mode in practice. When used as the last stage of a high power fiber amplifier, more than 90 W average power has been extracted at 1.03 μm wavelength with a slope efficiency of 75 % with respect to the absorbed pump power. These performances were obtained for a 6 m-long piece of fiber bent on a radius smaller than 12.5 cm. A mode field diameter of 35 μm is reported for the amplified beam with very good spatial quality and polarization extinction ratio.