Calculation of the optical forces exerted on a nano-dielectric sphere induced by a pulsed Laguerre-Gaussian beam.

Theoretically, we investigated the optical force exerted on a nano-dielectric sphere illuminated by a pulsed Laguerre-Gaussian beam. In the frame of the dipole approximation, analytical expressions for the optical force were derived. Based on these analytical expressions, the effects of pulse duration and beam mode order (,) on the optical force were studied. It is recognized that the optical force values and the trapping regions are remarkably affected by changing pulse duration and mode parameters. Our results show good agreement with the results obtained by other authors for the use of a continuous Laguerre-Gaussian beam and pulsed Gaussian beam.