On the Models of Nonlocal Nonlinear Optics. *

where D is a certain function of the electric field. For derivation of such type of equation see [1, 2]. Recent theoretical and experimental results highlight a very interesting phenomenology, such as “accessible solitons”, collapse arrest, optical vortices (see e.g. [3−6] and references therein), associated with so-called nonlocal nonlinear media. Most of the models studied before are not integrable and exact analytical solutions are not available for them. However, recently, it was shown that certain choice of nonlocal responses leads to 2 + 1-dimensional integrable models . In the present paper, for sake of simplicity we discuss the 1 + 1−dimensional case. In the section 2, we consider a more fundamental nonlocal nonlinear model than one considered in the paper [7]. We specify under which conditions it leads us to a generalization of the model discussed by Królikowski and Bang . The model proposed in [9] is of interest since