General coupled-mode analysis for gain-guided, index-antiguided fibers, and index-guided fibers

Coupling properties of two gain-guided index-antiguided (GG + IAG) fibers or GG+IAG fibers and index-guided (IG) fibers were investigated by the further general coupled mode theory The theory can explain any situation of two fiber coupling The interesting results were obtained by the numerical computation method For two GG + IAG fiber coupling total power was decreased as rising real-valued refractive-index difference (real part of refractive-index difference between core and cladding RVRID) while the power of one GG + IAG fiber was damped oscillations with Increased core separation In the GG + IAG fiber and IG fiber coupler the variation of the RVRID could change coupling characteristics These results are different from two IG fibers coupling and the general coupled-mode theory may provide meaningful references for new concepts of directional coupler and pumping technology of GG+IAG fiber Crown Copynght (C) 2010 Published by Elsevier BV All rights reserve