本文基于光波在宇称时间对称波导中传输的理论模型,数值研究各阶亮孤子在罗森莫尔斯势宇称时间对称波导中的传输特性。宇称时间对称波导的折射率分布对光具有线性聚焦作用,而增益/损耗分布可以引起光束能量的横向流动。研究结果表明: 当折射率调制深度为正时,一阶亮孤子在该波导中传输形成波浪形光束。当折射率调制深度为负时,一阶亮孤子分裂形成两束光,一束光发生弥散,另一束光以一定的速度向前传输,而增益/损耗调制深度会影响分裂后光束的传输行为;二阶亮孤子在较低的增益/损耗调制深度下传输形成稳定的呼吸光束;三阶亮孤子在传输过程中出现光波周期分裂与会聚现象;四阶及其以上高阶亮孤子在该波导中都不能稳定传输。此研究结果可为宇称时间对称在光波导中的应用提供一定的理论依据。

In this paper, based on the theoretical model of optical wave propagation in the parity time symmetric waveguide, the propagation characteristics of bright solitons in the Rosenmorse potential are studied numerically. The refractive index distribution of the parity-time symmetric waveguide has a linear focusing effect for beam, and the gain/loss distribution can cause the transverse energy-flow of beam. The results show that when the modulation depth of refractiveindex is positive, the first-order bright solitons can propagate and form a wavy beam in the waveguide. When the modulation depth is negative, the first-order bright soliton splits into two beams. One beam disappears and the other beam travels forward ata certain speed. The modulation depth of gain/loss can affect the propagation behavior of two beams. The second-order bright soliton can propagate and form a stable breathing beam under a lower modulation depth of the gain/loss. The third-order bright soliton appears splitting and converging periodically during the process of transmission. The fourth-order and higher order bright solitons cannot propagate stably in the waveguide. The results can provide a theoretical basis for the application of parity time symmetry in optical waveguides.