Nanooptics and photonics

Localized nonlinear waves in optical media with two interfaces
Gerasimchuk I.V.1,2, Gerasimchuk V.S.2, Pazyna Yu.A.2
1 Department of Physics of Meso- and Nanocrystal Magnetic Structures, Institute of Magnetism, Natl. Acad. of Sci. of Ukraine and Min. of Edu. and Sci. of Ukraine, Akad. Vernadsky Blvd. 36-b, Kyiv, 03142, Ukraine
E-mail: igor.gera@gmail.com
2 Faculty of Physics and Mathematics, National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute”, Peremohy Ave. 37, Kyiv, 03056, Ukraine

The study of propagation and the character of localization of nonlinear waves in optical systems with interfaces is one of the main problems of the dynamics of nonlinear waves and solitons. The simultaneous influence of the medium structure and nonlinearity can give rise to new physical effects such as spatial localization of nonlinear waves in modulated structures [1,2], dependence of the transparency of a medium on the power of the wave, etc. 
In the present work we study analytically the localized nonlinear waves propagating along two coupled parallel thin layers (interfaces) in an anharmonic focusing medium in the case of attractive character of both interfaces. In this case the nonlinear states are localized near the interfaces but the densities of two fluxes are equal only for small density of the total one [1]. We found analytically the localized antisymmetric soliton solution and demonstrate that it is governed by a single scaling variable which describe the ratio between the interface distance and the soliton state localization length. 
We found exactly the dependences of the total number of elementary excitations in the system and its total energy on the scaling variable characterizing the distance between the interfaces. Such universal scaling forms of the obtained dependences are valid for different values of the interfaces “power”. 
The present study can be useful for the description of localized states of nonlinear wave fluxes in optical media with interfaces. 

1.	Gerasimchuk I. V., Kovalev A. S. Localization of Nonlinear Waves in Layered Media // Low Temp. Phys.-2000.-26, No.8.-P. 586-593. 
2.	Gerasimchuk I. V., Kovalev A. S. Spatial Localization of Nonlinear Waves in Layered and Modulated Media // JETP Letters.-2007.-85, No.10.-P. 488–492.