A closed-form expression of the force on an infinite lossless dielectric cylinder illuminated by a TM incidence (electric field parallel to the cylinder’s axis) is derived. The formula, expressed as a simple sum, is straightforward to compute and is shown to be faster converging than the direct application of the Maxwell stress tensor and the expansion of the fields in the cylindrical coordinate system. A generalization of the formula to multiple incidences is provided and is illustrated by studying the force due to a Gaussian beam on cylinders of various parameters. We show in this way that the effects of the gradient of the intensity profile on the transverse and longitudinal confinements are decoupled, due to the permittivity contrast and to the size of the particle. Since the formula we derive is exact and is therefore not limited to the Rayleigh or ray optics regime, we expect it to be important for the modeling of optical forces on elongated particles of arbitrary sizes.
© 2007 Optical Society of America
Original Manuscript: August 30, 2006
Revised Manuscript: October 24, 2006
Manuscript Accepted: October 27, 2006
Published: February 15, 2007
Tomasz M. Grzegorczyk and Jin Au Kong, "Analytical expression of the force due to multiple TM plane-wave incidences on an infinite lossless dielectric circular cylinder of arbitrary size," J. Opt. Soc. Am. B 24, 644-652 (2007)