Observation of the bright photovoltaic spatial soliton in fiber-like photorefractive crystal

We have observed two-dimensional bright photorefractive spatial soliton for the first time in a Ce:KNSBN fiber-like crystal at wave-length of 514.5 nm with the intensity range between 2.83 × 10³ W/cm² and 4.71 × 10³ W/cm², then compared it with the one formed in a bulk sample. By comparison we have found that the intensity of forming a soliton in a fiber-like crystal is 7 9 times that in a bulk crystal due to stronger scattering light and complicated multi-wave interaction. By comparison we have also found that the transverse dimensions of a soliton formed in a fiber-like crystal are about 4% smaller than the ones in a bulk crystal when the experimental geometry remains the same, then we have exploited the theory including the contribution of scattering field to interpret the experimental phenomenon.