向列相液晶的饱和非线性及双稳态孤子  

Saturable nonlinearity and bistable solitons in nematic liquid crystals

作　　者：汪浩然 张银川 胡巍[1] 郭旗[1] Wang Hao-Ran;Zhang Yin-Chuan;Hu Wei;Guo Qi(Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices,South China Normal University,Guangzhou 510006,China)

机构地区：[1]华南师范大学广东省微纳光子功能材料与器件重点实验室,广州510006

出　　处：《物理学报》2023年第7期213-223,共11页Acta Physica Sinica

基　　金：广东省自然科学基金(批准号:2021A1515012214);广州市科技计划(批准号:2019050001)资助的课题.

摘　　要：本文讨论了正性向列相液晶的饱和非局域非线性.从光束在正性向列相液晶中传输满足的非线性耦合模型出发,分别讨论了1+1维和1+2维情况下液晶非线性折射率的饱和特性,并得到了在不同预偏角情况下,饱和双稳态孤子的数值解.结果表明:液晶中预偏角越大其饱和非线性折射率的值就越小,存在双稳态孤子的范围也越小;当非线性折射率饱和后,双稳态孤子之间的波形差异明显,且饱和情况下存在的孤子光斑不再是圆形.The saturated nonlocal nonlinearity of positive nematic liquid crystals(NLCa)is discussed in this paper.Based on the nonlinear coupling model satisfied by the beam propagation in a pocitive NLO,the saturable characteristics of the nonlinear refractive index(NRI)in the cases of 1+1 and 1+2 dimensions are discussed separately,and the numerical solutions of saturated bistable solitons for different pre-declination angles are obtained.The saturated NRI is smaller for larger pre-defletion angleo,and the center of the saturated NRI io almoct flat for different pre-deflection angles in 1+2 dimension.Solitono in the caturated case are no longer standard circular,whose waveforms in the s and y directions are slightly different.We also find that saturated bistable solitons can exist in NLOs for both 1+1 and 1+2 dimencions.With the inorease of pre-deflection angle,the existing regions of bistable solitons decrease,while their minimum beamwidth increases.Although the beamwidths of bistable solitons are the same,they have different powers and propagation constants,and their normalized soliton waveforms differ in the 1+2 dimensional case.

关 键 词：向列相液晶 非局域性 饱和非局域非线性 双稳态孤子 

分 类 号：O437[机械工程—光学工程]