摘要
采用严格耦合波理论,数值计算了不同参量下周期性极化铌酸锂晶体的电光衍射性质.研究表明:周期性极化铌酸锂晶体的周期性畴反转结构在电场的作用下相当于折射率衍射光栅,衍射性质和晶体的几何结构、周期、施加电场和入射角密切相关.以布喇格角度入射并满足布喇格衍射条件时,0级衍射光能量随施加电场的增大周期性地转化到-1级的衍射光中,最大转化效率达100%,增大周期性极化铌酸锂晶体的长度可以有效地降低转换电压值;以布喇格角度入射但光传输不满足布喇格衍射条件时,0级衍射光和-1级衍射光不能进行100%的能量转换,同时调制的周期性受到破坏.以布喇格角的倍数角入射时,0级光能量可以转化到相应的其他较高衍射级次,其中奇倍数衍射级的最大转换效率可达100%.研究结果为基于PPLN的集成电光器件设计提供有价值的参考.
Using the rigorous coupled wave theory, the electro-optical diffraction properties of periodically poled lithium niobate with different parameters were numerically studied. The analysis show that, the periodic domain structures of a periodically poled lithium niobate act as an index of refraction diffraction grating under the applied electric fields and its diffraction characters have relation to the geometry structures, the period, the applied electric fields and the incident angles. The periodically poled lithium niobate produces Bragg diffraction under the Bragg condition. In this case, the 0 order of diffraction light is periodically converted to --1 order of diffraction light with the increase of applying electric field. The maximum conversion efficiency can reach to 100% and the conversion voltage value can be reduced effectively by lengthening crystal. If angle of incidence is the Bragg angle, and the propagation of light in periodically poled lithium niobate does not satisfy the conditions of Bragg diffraction, the power of 0 order diffraction light can not transfer to i order of diffraction light with 100%. Meanwhile, the periodic modulation are damaged. The 0 order light is converted to corresponding multiple orders of diffraction lights with high diffraction efficiency when the incident angles are multiple Bragg angles. The maximum conversion efficiency is also reach 100%. The analysis results are helpful for developing the integrated devices of periodically poled lithium niobate.
出处
《光子学报》
EI
CAS
CSCD
北大核心
2014年第1期117-122,共6页
Acta Photonica Sinica
基金
国家自然科学基金(No.61367004)
广西自然科学基金创新团队项目(No.2013GXNSFFA019001)资助
关键词
周期性极化铌酸锂
电光效应
耦合波理论
布喇格衍射
衍射性质
Periodically poled lithium niobate
Electro-optical effect
Coupled wave theory
Braggdiffraction
Diffraction properties
