title: Array size scalability of passively coherently phased fiber laser arrays.
abstract: We explore, by means of experiments and simulation, the power combining efficiency and power fluctuation of coherently phased 2, 4, 6, 8, 10, 12, 14, 16-channel fiber-laser arrays using fused 50:50 single-mode couplers. The measured evolution of power combining efficiency with array size agrees with simulations based on a new propagation model. For our particular system the power fluctuations due to small wavelength-scale length variations are seen to scale with array size as N(3). Beat spectra support the notion that a lack of coherently-combined supermodes in arrays of increasing size leads to a decrease in combined-power efficiency.
authors.affiliation: Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, MI 48109-2099, USA. wzchang@umich.edu
authors.forename: Wei-zung
authors.initials: WZ
authors.lastname: Chang
authors.forename: Tsai-wei
authors.initials: TW
authors.lastname: Wu
authors.forename: Herbert G
authors.initials: HG
authors.lastname: Winful
authors.forename: Almantas
authors.initials: A
authors.lastname: Galvanauskas