高阶效应下对称三量子点系统中光孤子稳定性研究

Stability of optical soliton in symmetrical three-quantum-dot system under high-order effects

利用多重尺度法解析地研究了窄脉冲探测光激发下半导体三量子点分子系统中高阶效应对光孤子稳定性的影响.结果表明,由标准非线性薛定谔方程所描述的光孤子在传播的过程中会出现较大衰减,而由高阶非线性薛定谔方程所描述的光孤子却有着较为良好的稳定性.此外,数值模拟光孤子间的相互作用发现,由标准非线性薛定谔方程所描述的两光孤子碰撞后其振幅迅速衰减并辐射出较为严重色散波,而由高阶非线性薛定谔方程所描述的两光孤子碰撞后其形状几乎不发生任何变化.这主要是由于当入射的探测光脉冲足够窄时,系统须采用高阶方程来描述,其物理原因是方程中的高阶效应,包括非瞬时效应和三阶色散效应不能被忽略或当作微扰处理.这种稳定的光孤子对于将来的光信息处理和传输技术有着潜在的应用价值.

The influence of high-order effects on the stability of the optical soliton in a semiconductor three-quantum-dot molecular system under the excitation of narrow pulse probe light is analyzed analytically by using the multi-scale method.The results show that optical soliton described by the standard nonlinear Schrodinger equation will have a large attenuation in the propagation process,while the optical soliton described by the high-order nonlinear Schrodinger equation has relatively good stability.In addition,numerical simulations of the interaction between optical solitons show that the amplitudes of the two optical solitons described by the standard nonlinear Schrodinger equation attenuate rapidly after the collisions and radiation of more serious dispersion waves,while the shapes of the two optical solitons described by the high-order nonlinear Schrodinger equation hardly changes after the collision.This is mainly because when the incident probe light pulse is narrow enough,the system must be described by a higher-order equation.The physical reason is that the higher-order effects in the equation,including non-instantaneous effects and third-order dispersion effects,cannot be ignored or treated as perturbations.This kind of stable optical soliton has potential application value for future optical information processing and transmission technology.