摘要
大多数氧化物光折变晶体研究都没有考虑外加直流电场的影响。通过Kukhtarev材料方程得出施加直流电场时光折变晶体双波混频空间电荷场的材料方程,对比研究无外加电场和施加电场的情况下,归一化空间电荷场随归一化输入光强、归一化扩散场、中性施主与受主陷阱浓度比以及归一化外加直流电场的变化趋势;分析外加直流电场对增益系数的提升作用及其影响因素。结果表明:归一化扩散场较低时,施加直流电场可显著提升空间电荷场,有外加直流电场的空间电荷场明显高于无外加直流电场的空间电荷场。但是在归一化扩散场较高时,这种现象则不明显,此时空间电荷场受施加直流电场的影响较小;另外,当施加直流电场时,增益系数增加更多,并且在20-27 dBm/cm^(2)的最佳光强范围内达到饱和值。同时,最佳入射光强对应的峰值增益随着外加直流电场的增加而增大。所得结果可为光折变晶体双波混频的实际应用提供理论指导。
Most studies on oxide photorefractive crystals have not considered the influence of the external DC electric field.In this paper,space charge field in the photorefractive crystal is derived by solving the Kukhtarev's material rate equations in the presence of the external DC electric field.In the absence and presence of the external DC electric field,dependence of normalized space charge field on the normalized intensity ratio,normalized diffusion field,and concentration ratio are analyzed.Variation of the gain coefficient with external DC electric field is also investigated.The obtained results show that for the lower diffusion field the space charge field depends obviously on the external DC electric field,and the space charge field with the external DC electric field is appreciably higher than that without the external DC electric field.However,for the higher diffusion field the space charge field seems to be independent of the external DC electric field.In addition,when the DC electric field is applied,the improvement of the gain coefficient is higher and the saturation value is reached within the optimal intensity range of 20-27 dBm/cm^(2).Besides,the optimal incident light intensity corresponding to the peak gain increases with the augment of the external DC electric field.The results obtained can provide theoretical guidance for the practical application of two-wave mixing of photorefractive crystals.
作者
赵琰
陶传义
江旭海
肖建军
王豪
ZHAO Yan;TAO Chuanyi;JIANG Xuhai;XIAO Jianjun;WANG Hao(Department of Physics and Energy,Chongqing University of Technology,Chongqing 400054,China)
出处
《光电子．激光》
CAS
CSCD
北大核心
2021年第6期573-580,共8页
Journal of Optoelectronics·Laser
基金
国家自然科学基金(51874064)资助项目。
关键词
光折变晶体
空间电荷场
增益系数
直流电场
双波混频
photorefractive crystal
space charge field
gain coefficient
direct current electric field
two-wave mixing
