An investigation of the trapping force on a sphere in a tightly focused laser beam is carried out using a geometrical optics approximation. This calculation generalizes earlier work by allowing the spheres to be located off the beam axis. Additionally, a fifth-order, instead of zeroth-order, Gaussian approximation is used, and beam polarization is explicitly taken into account. The results suggest an interesting experiment, involving a driven damped harmonic oscilator system, which could be performed to test the validity of the theory. This experiment will be the focus of a future study.
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Knudson, Marc, "The Force on a Sphere in a Tightly Focused Laser Beam" (1993). Honors Theses, 1963-2015. 351.