Paraxial propagation of cosh-Airy vortex beams in chiral medium

Propagation dynamics of the cosh-Airy vortex(CAiV) beams in a chiral medium is investigated analytically with Huygens–Fresnel diffraction integral formula. The results show that the CAiV beams are split into the left circularly polarized vortex(LCPV) beams and the right circularly polarized vortex(RCPV) beams with different propagation trajectories in the chiral medium. We mainly investigate the effect of the cosh parameter on the propagation process of the CAiV beams.The propagation characteristics, including intensity distribution, propagation trajectory, peak intensity, main lobe's intensity, Poynting vector, and angular momentum are discussed in detail. We find that the cosh parameter affects the intensity distribution of the CAiV beams but not its propagation trajectory. As the cosh parameter increases, the distribution areas of the LCPV and RCPV beams become wider, and the side lobe's intensity and peak intensity become larger. Besides, the main lobe's intensity of the LCPV and RCPV beams increase with the increase of the cosh parameter at a farther propagation distance, which is confirmed by the variation trend of the Poynting vector. It is significant that we can vary the cosh parameter to control the intensity distribution, main lobe's intensity, and peak intensity of the CAiV beams without changing the propagation trajectory. Our results may provide some support for applications of the CAiV beams in optical micromanipulation.

双零色散介质中cosh-Airy脉冲超连续谱产生与操控

结合分步傅里叶方法和四阶Runge-Kutta积分法,研究了有限能量cosh-Airy脉冲在双零色散介质中的超连续谱产生与操控。首先,详细讨论了特征参数截断系数a、初始啁啾C和分布因子χ_(0)对cosh-Airy脉冲在双零色散介质中的演化影响,并统计了a、C和χ_(0)对超连续谱宽度的影响。然后,进一步研究了高阶非线性效应对cosh-Airy脉冲产生超连续谱的影响。结果表明:通过操控coshAiry脉冲的特征参数可以控制超连续谱的宽度;当存在高阶非线性效应时,超连续谱的平坦性会受到影响。研究结果为超连续谱的产生和操控以及宽带激光光源提供一些理论基础。