扭曲厄米-高斯-谢尔模光束对两种瑞利粒子的捕获

Trapping of two types of Rayleigh particles using focused twisted Hermite-Gaussian-Schell model beam

为探究聚焦扭曲厄米-高斯-谢尔模光束对瑞利粒子的捕获特性,基于广义惠更斯-菲涅耳原理和瑞利散射理论,推导了扭曲厄米-高斯-谢尔模光束经过聚焦透镜后光强和辐射力的解析表达式,并数值模拟分析了扭曲厄米-高斯-谢尔模光束对瑞利粒子的辐射力随光束阶数、扭曲因子等光束参数和透镜焦距的变化规律。结果表明,扭曲厄米-高斯-谢尔模光束的光场分布在传输过程中逐渐分裂并绕着传输轴旋转;梯度力和捕获稳定范围随着光束阶数和扭曲因子增大而增大;通过选择合适的光束参数和透镜焦距,可以实现对不同折射率的两种瑞利粒子的稳定捕获。研究结果对扭曲厄米-高斯-谢尔模光束在光镊技术中的应用具有一定的参考价值。

In order to explore the trapping properties of a focused twisted Hermite-Gaussian-Schell model beam on Rayleigh particles, based on the generalized Huygens-Fresnel principle and the Rayleigh scattering theory, the analytical expressions of light intensity and radiation force of a focused twisted HermiteGaussian-Schell model beam passing through a focused lens are derived, and then the effects of beam parameters such as beam order, twist factor and lens focal length on the radiation force of a focused twisted Hermite-Gaussian-Schell model beam are numerically simulated. The results show that the intensity distribution of a focused twisted Hermite-Gaussian-Schell model beam gradually splits and rotates around the transmission axis during the propagation, and the gradient force and trapping stable range of the beam increase with the beam order and twist factor. By selecting appropriate beam parameters and lens focal length, two types of Rayleigh particles with different refractive index can be stably trapped. The results are valuable for the application of focused twisted Hermite-Gaussian-Schell model beams in optical tweezers.