Spatial optical (2+1)-dimensional scalar- and vector-solitons in saturable nonlinear media

Abstract

2+1)-dimensional optical spatial solitons have become a major field of research in nonlinear physics throughout the last decade due to their potential in adaptive optical communication technologies. With the help of photorefractive crystals that supply the required type of nonlinearity for soliton generation, we are able to demonstrate experimentally the formation, the dynamic properties, and especially the interaction of solitary waves, which were so far only known from general soliton theory. Among the complex interaction scenarios of scalar solitons, we reveal a distinct behavior denoted as anomalous interaction, which is unique in soliton-supporting systems. Further on, we realize highly parallel, lightinduced waveguide configurations based on photorefractive screening solitons that give rise to technical applications towards waveguide couplers and dividers as well as all-optical information processing devices where light is controlled by light itself. Finally, we demonstrate the generation, stability and propagation dynamics of multi-component or vector solitons, multipole transverse optical structures bearing a complex geometry. In analogy to the particle-light dualism of scalar solitons, various types of vector solitons can -in a broader sense -be interpreted as molecules of light.

Solitonic lattices in photorefractive crystals

“…For this purpose the well-known interaction effects of spatial PR solitons can be exploited [2,7]. We utilize here a supplementary steering control beam derived from the Nd:YAG laser that can be focused anywhere on the front face of the crystal.…”

Interactions in large arrays of solitons in photorefractive crystals

“…For this purpose the well-known interaction effects of spatial PR solitons can be exploited [7,11]. We utilize here a supplementary control beam derived from the Nd:YAG laser that can be focused anywhere on the front face of the crystal (the steering beam in figure 1).…”

“…Varying the phase of the control beam relative to the phase of the array elements, a phase-sensitive coherent or incoherent interaction can be induced, that may lead to fusion or repulsion of different solitons in the array. Early experimental results for an incoherent control were presented in [4,7,10]. Here we display the influence of a phase-sensitive control beam obtained numerically, using experimental data from [4].…”

“…Spatial optical solitons are natural candidates for such applications, owing to their ability for self-adjustable waveguiding and versatile interaction capabilities, as demonstrated in light-induced Y and X couplers and beamsplitters, directional couplers and waveguides. In addition to such few-beam configurations, the geometries with many solitons propagating in parallel-the so-called soliton pixels, arrays or lattices-have been suggested for applications in information processing and image reconstruction [5][6][7][8].…”

“…Recently several groups demonstrated that quadratic arrays of spatial solitons can be formed in parametric amplifiers [8,9] or in PR media for coherent [7,10] and incoherent [4] beams.…”