Nonlinear Splitting of Optical Trap of Metallic Nanoparticles

Recently, the role of ultrafast pulsed excitation in laser trapping of dielectric nanoparticles has been explored [1-4] and it was observed that optical Kerr effect (OKE) plays an important role in determining the stability of the trap [2-4]. Here, we theoretically investigate trapping behaviour of metallic (silver) nanoparticles and studied the effect of OKE (up to sixth order) under high repetition-rate femtosecond pulsed excitation. We observe that the trapping potential well splits into two wells along axial direction, enabling the study of long-range interaction between the metal nanoparticles.