Photosoliton modes induced by cross–phase modulation in optical media conveying bright-dark vector solitons

Abstract

It is well known that high–intensity optical fields with soliton features, both bright and dark solitons, can trap and reshape photon fields of lower intensities into optical solitons by means of cross–phase modulation in optical materials with Kerr nonlinearity. In general the induced photon fields are not arbitrarily given, they are well-defined quantum states |ℓ, m〉 of a discrete spectrum which we refer to as quantum photosoliton modes. In this study we propose a scheme for the generation of quantum photosoliton states, by considering linear photon field propagating coupled to a vector high–intensity optical field with coexisting mutually transparent bright and dark solitons. It is found that features of the probe spectrum, specifically the nature, number and degeneracy of the associate quantum modes, depend on the strengths of couplings of the linear photon field to the bright and dark soliton components of the vector–soliton pump. The competition created by these simultaneous couplings leads to a rich variety of photosoliton modes, including modes that are replica of the soliton pump or translation modes of the two components of the vector–soliton pump. For the context where the optical pump consists of a single bright and a single dark soliton structures, it is found that photosoliton modes are all multiple degenerate in addition to being replica of some other modes. However, when the optical pump is a periodic multiplex of bright–dark solitons, photosoliton quantum states retain their identities (i.e. become non degenerate) but some of them are still either replica or translation modes of components of the optical pump.