Tunable evolutions of bright beams in a separate spatial soliton pair due to the crystal temperature

Abstract

We numerically investigate the temperature characteristics of the bright soliton and a Gaussian beam in a photorefractive crystal circuit, in which two photorefractive crystals are connected with an external voltage source. The results indicate that the dynamical evolution of the bright soliton and the Gaussian beam formed in one crystal depend strongly on the temperature of the other crystal, in which the dark soliton is formed. For the bright soliton, the full width at half maximum (FWHM) of the soliton increases and the center deflection decreases with the increase of the dark soliton crystal temperature. The Gaussian beam shows the similar evolution behaviors and experiences periodic compression and expansion during propagation. The deviation between the bright soliton and the Gaussian beam, however, becomes obvious as the increase of the temperature of the dark soliton crystal. A Gaussian beam that is mismatched with the bright soliton supported by the crystal could evolve into a bright solitary wave by tuning the temperature of the dark soliton crystal properly.