Open AccessAnalysis and experimental demonstration of spatial mode selection in a coherently combined fiber laser
Author(s) -
Erik Tilseth,
W. Minster Kunkel,
James R. Leger
Publication year - 2020
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.28.001854
Subject(s) - optics , resonator , fiber laser , laser , optical cavity , power (physics) , phase (matter) , beam (structure) , physics , optical fiber , normal mode , fiber , materials science , acoustics , vibration , composite material , quantum mechanics
Self-phasing due to spatial mode selection in a two-element passively coupled fiber laser is studied. We find that the addition of a second supermode in a coupled resonator results in a 90% increase in the average output power and nearly π/2 radians of passive phase adjustment versus applied phase errors between the gain elements. These results require a phase of zero (modulo 2π) between the beams in the external cavity. These findings are supported by an eigenmode analysis of the resonator and show that beam recycling is a useful resonator design feature but must be appropriately implemented to obtain beneficial results.