Optical solitons in multiple-core couplers with the nearest neighbors linear coupling

This paper addresses a type of nonlinear directional optical couplers with four different forms, namely the Kerr law, power law, parabolic law and dual-power law. The multiple-core couplers with the nearest neighbors linear coupling is studied with four forms of nonlinearity. Bright and dark optical solitons are obtained as well as Jacobi elliptic function solutions. The constraint conditions are acquired for the existence of solitons.