Abstract

Performance scaling of fiber lasers, especially ultrafast fiber lasers, has attracted much interest in the past few years driven by the demand for high energy, high peak power and high repetition rate sources. The first approach for mitigating nonlinearities relies on fabricating fibers with larger effective areas [1]. The second approach is coherent beam combination (CBC) which involves the amplification of a seed beam in separate channels and coherent combination at the output [2]. A multicore fiber (MCF) is essentially an integrated version of CBC and large mode area fibers. The fiber effective area increases with the number of cores and each core has to be phase locked for efficient combination. In this work, the applicability and limitations of an independent-core, ytterbium-doped multicore fiber for ultrafast pulse amplification and active coherent beam combination are investigated for the first time.

© 2015 IEEE