OPTICAL FIBER DESIGN METHOD

摘要

The purpose of the present invention is to provide: a beam propagation method that makes it possible to meet requirements regarding a desired output power, propagation distance, and beam quality; and an optical fiber design method for designing the structure of an optical fiber. In the present invention, the structure of an optical fiber is determined by calculating an effective core cross-sectional area Aeff on the basis of desired specifications and adjusting, as appropriate, the structure and the number of propagated modes of an optical fiber satisfying said core cross-sectional area Aeff. It is thus possible to achieve long-range propagation of high-output laser light while maintaining beam quality by controlling the excitation ratio of a high-order mode when coupling laser light to an optical fiber designed in this manner.