Rocking motion of an optical wing: theory

Abstract

The intensity-dependent rocking frequency of an illuminated semicylindrical refractive rod (or "optical wing") on a flat, nonslip surface is investigated. Both longitudinal and transverse radiation pressure forces (scatter and lift forces), as well as radiation pressure torque, transform the mechanical system into one having a bistable potential energy above a critical intensity. The equation of motion may be written as a parametrically driven nonlinear bistable harmonic oscillator, resulting in complex rocking dynamics. The effects of linear and sinusoidal intensity modulation schemes are explored, and experimental conditions to verify these results are discussed.

Theory and practice of simulation of optical tweezers

“…Another example is an optical "wing", consisting of a semi-cylindrical rod (Artusio-Glimpse et al, 2013;Simpson et al, 2012), Such a structure can generate lift-an optical force acting normal to the direction of illumination-in addition to the expected radiation pressure force. Simulations by Artusio-Glimpse et al (2014) show that complex rocking motion can occur. The simulations allow the effects of time-varying illumination, producing a parametrically driven nonlinear bistable oscillator, to be explored.…”