Abstract
We present a theoretical study of the one-dimensional modulational instability of a broad optical beam propagating in a biased photorefractive crystal with both linear and quadratic electro-optic effects(Kerr effect)under steady-state conditions.One-dimensional modulational instability growth rates are obtained by treating the space-charge field equation globally and locally.Both theoretical reasoning and numerical simulation show that both the global and local modulational instability gains are governed simultaneously by the strength and the polarity of external bias field and by the ratio of the intensity of the broad beam to that of the dark irradiance.Under a strong bias field,the results obtained using these two methods are in good agreement in the low spatial frequency regime.Moreover,the instability growth rate increases with the bias field,and the maximum instability growth occurs when ratio of light intensity to dark irradiance is 0.88.
基金项目
黑龙江省教育教学规划课题项目(GJB1320038)
黑龙江省教育教学规划课题项目(GJB1422173)
黑龙江省高校基础研究基金研究项目(KYYWF10236190106)
东北石油大学教育教学改革项目(JGXM_NEPU_202114)
东北石油大学主导创新基金项目(2021YDL-16)