Power scaling of Yb-doped large-mode-area fibers drives the scaling of the mode area in order to suppress nonlinearities. Two Yb-doped large-mode-area fibers were manufactured using the Direct Nanoparticle Deposition process: one with a step refractive index profile and active ion confinement, and another with a tailored refractive index and active ion confinement. The index tailoring and doping profiles were designed based on literature to enhance the beam quality of the fibers. Both fibers exhibited a mode field diameter comparable to a 40μm step index fiber with 0.07 NA. The fibers were characterized for their geometries, index profiles, and material composition profiles. Additional testing for beam quality and nonlinearities in pulsed operation was conducted using a power amplifier setup. The beam quality enhancement capability of the tested fibers was inconclusive due to incomparable launching conditions of the signal to the fibers.

Date Published: 17 February 2010
PDF: 9 pages
Proc. SPIE 7580, Fiber Lasers VII: Technology, Systems, and Applications, 758016 (17 February 2010); doi: 10.1117/12.842404

Published in SPIE Proceedings Vol. 7580:
Fiber Lasers VII: Technology, Systems, and Applications
Kanishka Tankala, Editor(s)