Pinning-induced round solitons with symmetric nonlinear response for electroactivated optical circuitry

The authors experimentally and theoretically study the formation of transient two-dimensional photorefractive spatial solitons in a striated paraelectric potassium lithium tantalate niobate crystal. The partial pinning to the built-in slablike index structures activates an interplay between the linear and nonlinear responses that leads to round solitons through a highly symmetric anisotropic nonlinearity, the means to self-write compact undistorted optical circuitry.