Guo Q L, Liang B L, Wang Y, Deng G Y, Jiang Y H, Zhang S H, Fu G S, Simmonds P J
Appl Opt. 2014 Oct 1;53(28):6422-6. doi: 10.1364/AO.53.006422.
The propagation characteristics of a focused laser beam in a SBN:75 photorefractive crystal strongly depend on the signal-to-background intensity ratio (R=I/I) under reverse external electric field. In the range 20>R>0.05, the laser beam shows enhanced self-defocusing behavior with increasing external electric field, while it shows self-focusing in the range 0.03>R>0.01. Spatial solitons are observed under a suitable reverse external electric field for R=0.025. A theoretical model is proposed to explain the experimental observations, which suggest a new type of soliton formation due to "enhancement" not "screening" of the external electrical field.
