Optical trapping of metallic nanoparticles has diverse applications because metallic nanoparticles have unique properties. One significant advantage is that the optical force exerted on metallic nanoparticles is considerably larger than that on dielectric nanoparticles of the same size and shape. This results in a significantly deeper optical potential well compared to the optical trapping of dielectric nanoparticles.
In this thesis, our central objective is to delve into the underlying physical mechanisms behind an exceptional and enhanced optical trapping phenomenon that is referred to as"nonlinear optical trapping". To achieve this, we extensively investigated the third-order nonlinear effects that come into play in this intriguing optical trapping behavior. This investigation aimed to shed light on the underlying principles and mechanisms that enable the manipulation of nanoparticles beyond the diffraction limit, opening up exciting possibilities for various applications in nanotechnology and beyond....