Abstract
Kilowatt class fiber laser sources have become ubiquitous in applications such as laser cutting and welding due to their excellent beam quality, and high efficiency [1]. A limiting effect for increasing power levels is transverse modal instability (TMI) [2,3], i.e., an oscillation of the output beam profile between the fundamental (LP01) mode, and one or more unintentionally amplified higher order modes (HOM) (usually LP11). Modal instability is facilitated by quantum defect heating of the fiber core [4], and can be mitigated by increasing the bend induced loss of the HOM [5,6]. However, increasing HOM loss by bending also increases LP01 loss, sometimes significantly, leading to an undesirable drop in device efficiency [5,6]. This work for the first time quantifies the impact of bend loss on efficiency for both constant diameter spools and a spiral.
© 2017 IEEE
PDF ArticleMore Like This
V. Scarnera, F. Ghiringhelli, M.K. Durkin, C.A. Codemard, and M.N. Zervas
CJ_6_2 The European Conference on Lasers and Electro-Optics (CLEO/Europe) 2017
J. Limpert, C. Jauregui, H.-J. Otto, F. Stutzki, F. Jansen, T. Eidam, and A. Tünnermann
ATu1A.2 Advanced Solid State Lasers (ASSL) 2013
Franz Beier, B. Sattler, A. Liem, N. Haarlammert, Thomas Schreiber, Ramona Eberhardt, and Andreas Tünnermann
JTu2A.32 Advanced Solid State Lasers (ASSL) 2017