Abstract

Large core microstructured fibers are intensively investigated because of their application in the area of laser physics and high-power light transfer to decrease the non-linear processes. In holey fibers with solid glass core single-mode regime becomes the endless one over the spectra and the most suitable manner of core increasing is scaling of the fiber dimensions without any change in the fiber structure. But the investigations [1] of the endlessly single-mode large-core fibers have shown the main problem: increase of the core diameter leads to the shift of the modal leaking boundary to the long-wavelength region. In [2] the authors managed to increase the core (comprised of 7 or 19 central elements) diameter up to 35 and 50μm and to obtain the laser generation, but no evidence about the modal consistence has been presented. In this work we have determined the conditions under which the fiber practically supports only fundamental mode due to strong attenuation of the higher order modes.

© 2009 IEEE