Manakov solitons in unbiased photorefractive materials with both the pyroelectric effect and photovoltaic effect

Abstract

We have shown, for the first time, the existence of Manakov solitons in unbiased photorefractive crystals exhibiting both, the pyroelectric effect and the bulk photovoltaic effect for all three realizations, namely bright-bright, dark-dark, and bright-dark. The two mutually incoherent beams should have the same wavelength and polarization and the total intensity of the two beams should be much smaller than the effective dark irradiance. Analytical solutions for the soliton pair are found out for all three cases. The intensity full width at half maximum and hence the existence curves are found out for all three realizations. The Manakov soliton pair width depends on the magnitude of both, the transient pyroelectric field and the bulk photovoltaic field. The interplay between the photovoltaic effect and the pyroelectric effect in the self trapping process is investigated. Relevant example of a lithium niobate crystal is considered to illustrate our results.