One-dimensional steady-state photorefractive screening solitons

Abstract

We study one-dimensional steady-state photorefractive screening solitons in a bulk strontium barium niobate crystal. We compare measurements and calculations of the soliton properties and find good agreement for relations between the profile, width and intensity of the soliton, the applied voltage and material parameters. We find the solitons stable against perturbations both in the plane and perpendicular to the plane of the soliton for intensities large compared to the background intensity.

High-intensity nanosecond photorefractive spatial solitons

“…It is apparent that there is good agreement between experiments and theory for both the high-and the low-intensity cases. The predominant reason for the discrepancy is that the background beam is slightly guided by the refractive-index change induced by the soliton 10 (since r 13 is not zero) rather than maintaining a constant value across the beam as is assumed theoretically.…”

“…We refer to this curve as the soliton existence curve. This curve is important because experiments show that considerable deviations (ϳ20% or more) from the curve lead to instability and breakup of the soliton beam, 10,22 whereas much smaller deviations are typically tolerated and are arrested by the soliton stability properties. In the case of a low-intensity photorefractive soliton beam, i.e., a beam with an intensity in the mW͞cm 2 to kW͞cm 2 range, recent 1D experiments have known good agreement with this universal relationship.…”

“…In the case of a low-intensity photorefractive soliton beam, i.e., a beam with an intensity in the mW͞cm 2 to kW͞cm 2 range, recent 1D experiments have known good agreement with this universal relationship. 10,20 Although the low-intensity feature of photorefractive spatial solitons is attractive for applications, high-intensity ͑MW͞cm 2 to GW͞cm 2 ͒ photorefractive solitons are also interesting, since the speed with which the steady-state screening soliton forms is inversely proportional to the optical intensity. As we show below, solitons in strontium barium niobate (SBN) can form at nanosecond speeds for GW͞cm 2 intensities, which implies that for photorefractive semiconductors, which have mobilities 100 -1000 times larger than those of the photorefractive oxides, soliton formation should occur at picosecond time scales for similar intensities.…”

Coherent collisions of photorefractive solitons

“…Incoherent collisions between photorefractive solitons 17 were found to be subject to the optical guiding properties of the waveguides induced by each of the solitons, which in turn are controlled by the soliton existence curve. 18 Here we study coherent collisions between photorefractive solitons. Coherent collisions will be subject to (a) the waveguiding properties of the soliton-induced intersecting waveguides, 19 which apply to all interacting solitons; (b) coherent attraction -repulsion forces, which apply to coherent soliton interactions only, and (c) two-beam-coupling processes, which apply to photorefractive spatial solitons only.…”

Experimental control of steady state photorefractive self-focusing in InP:Fe at infrared wavelengths

“…Since their first observation [3,4], the PR solitons have been extensively characterized from experimental and theoretical point of view. As such, their properties are well known in typical PR materials (such as SBN, Bi 12 TiO 20 and BaTiO 3 [5][6][7][8]), in which the PR effect is due mainly to only one type of charge carriers and occurs at visible wavelengths. The dynamics of self focusing and soliton formation have been studied and characterized at steady state [9][10][11][12] as well as in transient regime [13,14], together with its dependency on various parameters (temperature, background illumination) for two different iron dopings.…”