耦合暗孤子在自散焦介质中的传输特性  

Propagation Characteristics of Coupled Dark Solitons in Self-defocusing Media

作　　者：王锦丽 钟春晓 任喜梅 李蓉 WANG Jin-li;ZHONG Chun-xiao;REN Xi-mei;LI Rong(Nanchang Jiao-Tong Institute,Nanchang 330100,China)

机构地区：[1]南昌交通学院,江西南昌330100

出　　处：《量子光学学报》2021年第3期213-218,共6页Journal of Quantum Optics

基　　金：江西省教育厅科学技术研究项目(GJJ181493)。

摘　　要：空间光孤子是介质衍射效应和非线性效应相平衡的结果.当两束非相干光在非线性介质中传输时,两孤子发生交叠而产生相互作用,本文研究自散焦介质中非相干耦合暗孤子对的传输特性和相互作用.基于描述光束传播的耦合非线性薛定谔方程组,利用变分法,首先得到了自散焦克尔介质中传输的两暗孤子的幅值、横向中心位置坐标、速度和相位随传输距离变化的参数演化方程组,讨论了孤子参数演化的规律.然后,为分析孤子间相互作用,导出了两幅值相等的暗孤子在传输过程中孤子间距随传输距离的变化规律,作出了孤子对传输图像和相互作用图像,最后导出了孤子间相互作用势能和相互作用力的表达式,并利用图像详细分析了孤子间的相互作用特性.研究结果表明:无损耗情况下,孤子的幅值不受耦合作用的影响,传输过程中保持不变;耦合相互作用使两孤子横向中心位置坐标发生明显漂移,当两孤子间距较小时,孤子间距随传输距离作变速变化,变化速率与孤子的幅值和耦合程度有关,当两孤子间距趋近于零时,孤子间距随传输距离呈匀速的稳定变化;暗孤子间的相互作用力为排斥力,随着孤子间距增大,排斥力先增大后减小,而相互作用势能一直逐渐减小,当孤子间距增至4.5附近时,孤子间势能减小到几乎为零.Spatial optical soliton is the result of the balance between diffraction and nonlinear effect when light propagates in nonlinear media.The soliton pair can overlap and interact when two beams of incoherent light propagate in a nonlinear medium.The propagation characteristics and interaction of incoherently coupled dark soliton pairs in self-defocusing media were studied.By using the variational method,the parameter evolution equations of two dark solitons propagating in self-defocusing Kerr media were obtained based on the coupled nonlinear Schrödinger equations which describe beam propagation.First,the parameter evolution equations of two dark solitons propagating in self-defocusing Kerr media were obtained,and the evolution rules of soliton parameters were discussed.Then,in order to analyze the interaction between solitons,the function of the distance between two dark solitons with equal amplitude was derived,and the soliton pair transmission image and interaction image were given.Finally,the expressions of interaction potential energy and interaction force between solitons were derived,and the interaction characteristics between solitons were analyzed in detail by using images.The results show that the amplitude of the solitons is not affected by the coupling effect in the case of no loss and remains unchanged in the transmission process.The coupling interaction makes the coordinates of the two solitons shift obviously.When the distance between the two solitons is small,the distance between the two solitons varies with the transmission distance,and the change rate is related to the amplitude and coupling coefficient of the solitons.When the distance between the two solitons approaches zero,the distance between the two solitons changes steadily with the transmission distance.The interaction force between dark solitons is repulsive.With the decrease of the distance between solitons,the repulsive force first increases and then decreases,but the interaction potential energy gradually decreases.When the distance b

关 键 词：非线性光学 暗孤子 变分法 自散焦 非相干 

分 类 号：O431[机械工程—光学工程]