The surface waves propagating along the contact between the layer with the constant gradient of refractive index and photorefractive crystal

Abstract

We consider the photorefractive crystal with diffusion nonlinearity mechanism contacting with the linearly graded-index medium. The new types of the surface waves propagating along the contact are found and their properties are described. The transition between two types of the surface waves can be controlled by the waveguide temperature. The light field penetrates into the photorefractive crystal much deeper than into the graded-index medium. The maxima intensity monotonically increase with an increase in the propagation constant, and monotonically decrease with an increase in the temperature. The localization length of the surface waves decreases with an increase in the characteristic distance the graded-index medium and with a decrease in the propagation constant and the temperature. The discrete spectrum of the propagation constant for the special waveguide mode corresponding to the case of exponential damping of intensity maxima of the surface waves with an increasing temperature is obtained. It is shown that the intensity maxima in the photorefractive crystal depend parabolic on the temperature at low temperature waveguide mode.

Light localization in a linearly graded-index substrate covered by intensity dependent nonlinear self-focusing cladding

“…The two types of the surface waves were found. The solution of the wave equation in the half-space containing the graded index layer presented in [45] is similar to the part of equation ( 6) at z > 0, which are expressed by the Airy function. The electric filed oscillations were detected in the photorefractive crystal half-space.…”

“…The media containing the graded-index layer were considered in our recent papers [44,45]. The contact of media with the graded-index layer and photorefractive crystal was described in [45]. The two types of the surface waves were found.…”

“…Here we calculate and analyze the light localization near the interface between the graded-index substrate and the selffocusing nonlinear cover with α 1,2 > 0. Then we obtain the light intensity distribution across the interface in the range of the effective refractive index max{ε 1 , ε 2 } < n 2 < ε 0 [44,45]:…”

“…We described the new type of the composite planar waveguide characterized by unique optical properties caused by the special selection of the waveguide structure consisting of the linearly gradedindex layer and medium characterized by a sharp appearance of self-focusing Kerr type nonlinear response [44]. The waveguide consisting of the contacting semi-infinite photorefractive crystal and graded-index semi-infinite medium was considered in [45].…”

Surface waves propagating along the interface between a parabolic graded-index medium and a self-focusing nonlinear medium: exact analytical solution

“…Recently, we describe analytically surface waves propagating along the contact between the linearly graded-index layer and photorefractive crystal [60]. We find also the exact analytical solutions describing the surface waves propagating along the contact between the linearly graded-index layer and crystal with the layer, in which the Kerr nonlinear response appears with increasing the electric field [61].…”