We analyze the characteristics of the radiation force that is generated when a highly focused unpolarized Gaussian beam interacts with a nonabsorbing microsphere whose refractive index exhibits a first-order dependence on the beam intensity. The behavior of the force exerted on the sphere is analyzed as a function of beam power, axial distance, sphere radius, refractive-index difference between the sphere and the surrounding liquid, and wavelength. The force characteristics are compared with those of the radiation force that is generated when the electro-optic Kerr effect is absent. Our results show that a reversal in the net force direction is introduced when the Kerr effect becomes significant, which occurs at sufficiently high beam intensities.
© 1997 Optical Society of America
Original Manuscript: February 20, 1996
Revised Manuscript: July 22, 1996
Published: May 20, 1997
Romeric Pobre and Caesar Saloma, "Single Gaussian beam interaction with a Kerr microsphere: characteristics of the radiation force," Appl. Opt. 36, 3515-3520 (1997)