Simultaneous Trapping of Two Types of Particles with Focused Elegant Third-Order Hermite–Gaussian Beams

The focusing properties of elegant third-order Hermite–Gaussian beams (TH(3)GBs) and the radiation forces exerted on dielectric spherical particles produced by such beams in the Rayleigh scattering regime have been theoretically studied. Numerical results indicate that the elegant TH(3)GBs can be used to simultaneously trap and manipulate nanosized dielectric spheres with refractive indexes lower than the surrounding medium at the focus and those with refractive indexes larger than the surrounding medium in the focal vicinity. Furthermore, by changing the radius of the beam waist, the transverse trapping range and stiffness at the focal plane can be changed.