SOLITON SWITCHING IN 3-CORE NONLINEAR DIRECTIONAL FIBER COUPLERS

We present an analytical investigation of the propagation and the swit ching of fundamental solitons in a three-core nonlinear fiber coupler with a variational method using the Lagrangian density formulation. Th e analytical solutions were obtained directly from the coupled nonline ar Schrodinger equations. The transmission characteristics of first or der solitons obtained by the analytical procedure agree well with the results from numerical analysis. Three different geometries for the no nlinear three-core directional coupler were studied. Taking into accou nt the length of the coupler and the critical power a comparative stud y between these geometries was done. (C) 1998 American Institute of Ph ysics. [S0021-8979(98)05916-7]