Abstract
Cladding-pumped fibers with high numerical aperture (NA) are commonly used in high-power lasers and amplifiers, which require the capture of pump light from low-brightness laser diodes. However, rays launched off-center into cladding-pumped fibers are less efficiently absorbed [1]. These skew rays follow a helical off-center path, have no overlap with the doped core and are not absorbed. Experiments show that skew rays can be suppressed by breaking the cylindrical symmetry of the inner cladding e.g. by using the technique of periodic bending of the fiber. Furthermore, it has been suggested that the pump absorption efficiency can be increased by including a small circular scatterer, which changes the ray pattern and induces chaotic dynamics in the fiber [2]. Suppression of skew rays is an important issue in the optimization of high power fiber lasers and amplifiers. Photonic crystal fibers inherently contain several small circular scatterers due to the hole structure in the pump cladding and are therefore expected to be less sensitive to skew rays than a traditional step index fiber. The aim of the experiment is to investigate the skew ray scrambling effect of the hole structure in photonic crystal fibers compared to the commonly used periodic bending method for step index fibers.
© 2009 IEEE
PDF ArticleMore Like This
T. A. Birkst, D. Mogilevtsev, J. C. Knight, P. St.J. Russell, J. Broeng, P. J. Roberts, J. A. West, D. C. Allan, and J. C. Fajardo
FG4 Optical Fiber Communication Conference (OFC) 1999
H. Yoshida, K. Tsubakimoto, H. Fujita, N. Miyanaga, and M. Nakatsuka
CJ_P4 The European Conference on Lasers and Electro-Optics (CLEO/Europe) 2009
F. Poli, J. Lægsgaard, D. Passaro, A. Cucinotta, S. Selleri, and J. Broeng
CJ_P22 The European Conference on Lasers and Electro-Optics (CLEO/Europe) 2009