有偏压的光伏光折变晶体中的空间孤子

证明了有偏压的光伏光折变晶体中存在着明、暗稳态的空间孤子.它源于对外电场的非均匀空间屏蔽和光伏效应.与已报道的稳态光折变空间孤子相比，它具有不同的特性.当外电场为某一特定值时，用改变外电场的极性和旋转光的偏振方向可以实现明孤子与暗孤子的相互转换.当外电场足够强可以忽略光伏效应时，它类似于屏蔽孤子；当不存在外电场时，它类似于开路条件下的光伏孤子. 关键词：

SPATIAL SOLITONS IN PHOTOVOLTAIC PHOTOREFRACTIVE CRYSTALS IN AN EXTERNAL BIAS FIELD

Bright and dark spatial solitons are predicted for biased photovoltaic photorefractive crystals, which are due to both the spatially nonuniform screening of the external electric field and the photovoltaic effect. These solitons differ form previously observed photorefractive spatial solitons in their properties. When external electric field is of a certain value, these solitons may be switched from bright to dark both by changing the polarity of the external electric field and by rotating the polarization of the light. In case the effect of the external bias field is much stronger than the photovoltaic effect and the latter can be neglected, these solitons are similar to screening solitons. In case the external bias field is absent, these solitons are similar to photovoltaic solitons in the open-circuit case.