基于光波在PT(Parity-Time)对称波导中传输的理论模型,采用数值模拟研究了高斯光波在高斯型PT对称克尔非线性平板波导中的传输控制特性。PT对称波导要求其折射率分布呈偶对称,而增益/损耗分布呈奇对称。研究结果表明:在高斯型PT对称波导中,基模高斯光波可以形成波浪形光束,并稳定地传输;随着折射率分布强度的增加,波浪形光束的振荡频率增加,振荡幅度减小。一阶高斯光波在PT对称波导中传输时,在折射率较大的条件下,两束光可以被束缚在波导中心稳定地传输,而二阶高斯光波则需要更大的折射率分布强度才能被束缚。该研究结果可为PT对称波导在全光开关控制上的应用奠定理论基础。

The propagation control characteristic of Gaussian optical waves in parity-time (PT)-symmetric Kerr nonlinear planar waveguide with a Gaussian distribution is numerically studied based on the theoretical model of the optical-wave propagation in a PT-symmetric waveguide. The PT-symmetric waveguide requires the refractive-index distribution of the waveguide to have an even symmetry, whereas the gain/loss distribution must be odd. The results demonstrate that in the Gaussian PT-symmetric waveguide, the fundamental-mode Gaussian optical wave can form a wave-shaped beam that has a stable propagation. When the strength of the refractive-index distribution is increased, the oscillation frequency of the wave-shaped beam increases and the oscillation amplitude decreases. When the refractive index becomes larger, the two beams of the first-order Gaussian optical wave in the PT-symmetric waveguide can be restricted at the center of the waveguide, allowing stable propagation of the two beams. The second-order Gaussian optical wave requires a stronger refractive-index distribution for it to be restricted. This work lays a theoretical foundation for the application of PT-symmetric waveguide in all-optical switching control.