Coupling of optical spatial solitons in photorefractive multiple quantum well planar waveguide

A comprehensive theory predicting the existence of both incoherently coupled and coherently coupled grey and dark optical spatial solitons in multiple quantum well planar (MQW) waveguides is presented. In addition, we also show the existence of dark Manakov soliton pair and the bright-dark Manakov soliton pair in such Multiple Quantum well waveguides for the first time. In the case of a coherently coupled soliton pair, the mutual phase difference, the overlap of the optical mode on the waveguide, the external bias field and beam intensity ratio have a profound effect on the FWHM of the soliton pairs. As a general case, a theory for the interesting and hitherto uninvestigated case of coherently coupled multicomponent solitons has been presented and analyzed for the first time. The effect of the mutual phase difference, the overlap of the optical mode on the waveguide(overlap parameter), the external bias field and beam intensity ratio on the FWHM is studied for these coherently coupled multicomponent solitons also. The Manakov soliton solutions are found analytically and they exist in the limit of low total intensity of the beams We find that the dark-dark and bright-dark Manakov soliton pairs exist in such MQW waveguides whereas bright-bright Manakov soliton pair does not exist. The Manakov solitons' spatial profile depends upon the overlap parameter, the intensity of the components, and the external electric field.